Computer Certification

To earn your Cisco CCNA and CCNP certifications
you've got to master ISDN - and despite what some people say
there's still a lot of ISDN out there that needs to be supported. And when it comes to troubleshooting ISDN
there's a lot to look at. Is the correct ISDN switchtype configured? Are the dialer map statements correct? What about the dialer-group and dialer-list commands? And that's just the start.

I always say that all troubleshooting starts at Layer 1
the Physical layer of the OSI model. The usual method of troubleshooting ISDN is sending pings across the link
but the connection can be tested without using pings or even before assigning IP addresses to the BRI interfaces!

It's a good idea to place these test calls before configuring the interfaces - that way
you know you've got a valid connection before beginning the configuration (and there's a lot of config to go along with ISDN!)

To place a test call without using pings
use the isdn call interface command.

R1#isdn call interface bri0 8358662

R1#

03:54:43: BR0 DDR: Attempting to dial 8358662

03:54:43: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up

03:54:44: BR0:1 DDR: dialer protocol up

03:54:45: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to up

03:54:49: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8358662 R2

To tear the test call down correctly
use isdn disconnect interface. IOS Help displays the options with this command.

R1#isdn disconnect interface bri 0 ?

all Disconnect the data call(s) on all b channels

b1 Disconnect the data call on b1 channel

b2 Disconnect the data call on b2 channel

R1#isdn disconnect interface bri 0 all

03:58:36: BR0:1 DDR: disconnecting call

03:58:36: BR0:2 DDR: disconnecting call

03:58:36: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 8358662
R2
call lasted 20 seconds

03:58:36: %LINK-3-UPDOWN: Interface BRI0:1
changed state to down

03:58:36: BR0:1 DDR: disconnecting call

03:58:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to down

I say "correctly" because the one thing you don't want to do to end an ISDN call
test or otherwise
is just shut the interface. Telcos don't like it
and ISDN lab devices like it even less. Always let the d-channel do its work and tear the call down in an orderly fashion - don't just cut it off by shutting the interface down.

To earn your Cisco CCNA and CCNP certifications
you've got to master ISDN - and despite what some people say
there's still a lot of ISDN out there that needs to be supported. And when it comes to troubleshooting ISDN
there's a lot to look at. Is the correct ISDN switchtype configured? Are the dialer map statements correct? What about the dialer-group and dialer-list commands? And that's just the start.

I always say that all troubleshooting starts at Layer 1
the Physical layer of the OSI model. The usual method of troubleshooting ISDN is sending pings across the link
but the connection can be tested without using pings or even before assigning IP addresses to the BRI interfaces!

It's a good idea to place these test calls before configuring the interfaces - that way
you know you've got a valid connection before beginning the configuration (and there's a lot of config to go along with ISDN!)

To place a test call without using pings
use the isdn call interface command.

R1#isdn call interface bri0 8358662

R1#

03:54:43: BR0 DDR: Attempting to dial 8358662

03:54:43: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up

03:54:44: BR0:1 DDR: dialer protocol up

03:54:45: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to up

03:54:49: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8358662 R2

To tear the test call down correctly
use isdn disconnect interface. IOS Help displays the options with this command.

R1#isdn disconnect interface bri 0 ?

all Disconnect the data call(s) on all b channels

b1 Disconnect the data call on b1 channel

b2 Disconnect the data call on b2 channel

R1#isdn disconnect interface bri 0 all

03:58:36: BR0:1 DDR: disconnecting call

03:58:36: BR0:2 DDR: disconnecting call

03:58:36: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 8358662
R2
call lasted 20 seconds

03:58:36: %LINK-3-UPDOWN: Interface BRI0:1
changed state to down

03:58:36: BR0:1 DDR: disconnecting call

03:58:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to down

I say "correctly" because the one thing you don't want to do to end an ISDN call
test or otherwise
is just shut the interface. Telcos don't like it
and ISDN lab devices like it even less. Always let the d-channel do its work and tear the call down in an orderly fashion - don't just cut it off by shutting the interface down.

One of the first things you learned about Frame is that the LMI also serves as a keepalive
or a heartbeat - and if three consecutive LMIs are missed
the line protocol goes down. There's a limitation to LMI as a keepalive
though. The LMI is exchanged only between the DTE and the closest DCE. The LMI is therefore a local keepalive that does not reflect any possible issues on the remote end of the virtual circuit.

Taking the LMI concept to the next logical level
Frame Relay End-To-End Keepalives (FREEK
one of the least-heard Cisco acronyms for some reason) are used to verify that endpoint-to-endpoint communications are functioning properly.

What you have to keep in mind about FREEK is that each and every PVC needs two separate keepalive processes. Remember
with a PVC
there's no guarantee that the path taking through the frame relay cloud to get from R1 to R2 is going to be the same path taken to go back from R2 to R1. One process will be used to send requests for information and handle the responses to these requests; this is the send side. When the send side transmits a keepalive request
a response is expected in a certain number of seconds. If one is not received
an error event is noted. If enough error events are recorded
the VC's keepalive status is marked as down.

The process that responds to the other side's requests is the receive side.

This being Cisco
we've got to have some modes
right? FREEK has four operational modes.

Bidirectional mode enables both the send and receive process enabled on the router
meaning that the router will send requests and process responses (send side) and will also respond to remote requests for information (receive side).

Request mode enables only the send process. The router will send requests and process responses to those requests
but will not answer requests from other routers.

Reply mode enables only the receive process. The router will respond to requests from other routers but will initiate no requests of its own.

Finally
passive reply mode allows the router to respond to requests
but no timers are set and no events are tracked.

Frame Relay End-To-End Keepalive defaults:

Two send or receive errors must be registered in order for the VC to be considered down.

The event window size is three. The event window is the number of events considered by the router when determining the status of the VC. Therefore
using the defaults
two send or receive errors would have to be received within the event window of three events for the VC to be considered down.

The timer mentioned earlier - the amount of time a router waits for a response - is set to 10 seconds

Working with Frame Relay end-to-end keepalives is just one Frame skill you’ll need to pass the CCNP exams – and I wouldn’t be surprised to see them on a CCIE exam. Know the details and you’re on your way to Cisco certification exam success!

You may run into situations where a router in a remote location needs to dial in to a central router
but the toll charges are much higher if the remote router makes the call. This scenario is perfect for PPP Callback
where the callback client places a call to a callback server
authentication takes place
and the server then hangs up on the client! This ensures that the client isn't charged for the call. The server then calls the client back.


In the following example
R2 has been configured as the client and R1 is the callback server. Let's look at both configurations and the unique commands PPP Callback requires.

Client:

username R1 password CCIE

interface BRI0

ip address 172.12.12.2 255.255.255.0

encapsulation ppp

dialer map ip 172.12.12.1 name R1 broadcast 5557777

dialer-group 1

isdn switch-type basic-ni

ppp callback request

ppp authentication chap

Most of that configuration will look familiar to you
but the ppp callback request command might not. This command enables the BRI interface to request the callback.

Simple enough
right? The PPP Callback Server config requires more configuration and an additional map-class as well.

Server:

username R2 password CCIE
interface BRI0

ip address 172.12.12.1 255.255.255.0

encapsulation ppp

dialer callback-secure

dialer map ip 172.12.12.2 name R2 class CALL_R2_BACK broadcast 5558888

dialer-group 1

isdn switch-type basic-ni

ppp callback accept

ppp authentication chap

map-class dialer CALL_R2_BACK

dialer callback-server username


Examining the PPP Callback Server command from the top down...


dialer callback-secure enables security on the callback. If the remote router cannot be authenticated for callback
the incoming call will be disconnected.


The dialer map statement now calls the class CALL_R2_BACK
shown at the bottom of the config excerpt.


ppp callback accept enables PPP callback on this router.


dialer callback-server username tells the callback server that the device referenced in the dialer map statement is a callback client.


The only way to find out if the config works is to test it
so let's send a ping from R2 to R1 and see if the callback takes place.


R2#ping 172.12.12.1


Type escape sequence to abort.

Sending 5
100
ICMP Echos to 172.12.12.1
timeout is 2 seconds:

02:45:42: BR0 DDR: Dialing cause ip (s=172.12.12.2
d=172.12.12.1)

02:45:42: BR0 DDR: Attempting to dial 5557777

02:45:42: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up

02:45:42: BR0:1 DDR: Callback negotiated - Disconnecting now

02:45:42: BR0:1 DDR: disconnecting call

02:45:42: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 5557777 R1

02:45:42: %LINK-3-UPDOWN: Interface BRI0:1
changed state to down

02:45:42: DDR: Callback client for R1 5557777 created

02:45:42: BR0:1 DDR: disconnecting call.....

Success rate is 0 percent (0/5)

R2#

02:45:57: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up

R2#

02:45:57: BR0:1 DDR: Callback received from R1 5557777

02:45:57: DDR: Freeing callback to R1 5557777

02:45:57: BR0:1 DDR: dialer protocol up

02:45:58: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to up

The callback was successfully negotiated
and the call then disconnected. R1 then called R2 back
and show dialer on R1 confirms the purpose of the call.

R1#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last DNIS Last status

5558888 2 4 00:00:20 successful

0 incoming call(s) have been screened.

0 incoming call(s) rejected for callback.

BRI0:1 - dialer type = ISDN

Idle timer (120 secs)
Fast idle timer (20 secs)

Wait for carrier (30 secs)
Re-enable (15 secs)

Dialer state is data link layer up

Dial reason: Callback return call

Time until disconnect 99 secs

Connected to 5558888 (R2)

Pretty cool! PPP Callback isn’t just important for passing your CCNA and CCNP exams – in circumstances such as shown in this example
it can save your organization quite a bit of money!

ISDN is a huge topic on both your Cisco CCNA and BCRAN CCNP exams. While many ISDN topics seem straightforward
it’s the details that make the difference in the exam room and working with ISDN in production networks. Configuring and troubleshooting multilink PPP is just one of the skills you’ll need to pass both of these demanding exams.

With BRI
we've got two B-channels to carry data
and both of them have a 64-kbps capacity. You might think it would be a good idea to have both channels in operation before one reaches capacity
and it is a great idea Problem is
it's not a default behavior of ISDN. The second b-channel will not begin to carry traffic until the first one reaches capacity.

With Multilink PPP (MLP)
a bandwidth capacity can be set that will allow the second b-channel to bear data before the first channel reaches capacity. The configuration for MLP is simple
but often misconfigured. We'll use our good friend IOS Help to verify the measurement this command uses.

Enabling MLP is a three-step process:

Enable PPP on the link

Enable MLP with the command ppp multilink

Define the threshold at which the second b-channel should start carrying data with the dialer load-threshold command.

Let's say you wanted the second b-channel to start carrying data when the first channel reaches 75% of capacity. It would make sense that the command to do so would be dialer load-threshold 75... but it's not.

R1(config)#int bri0

R1(config-if)#ppp multilink

R1(config-if)#dialer load-threshold ?

<1-255> Load threshold to place another call

The dialer load-threshold value is based on 255
not 100. To have this command bring the line up at a certain percentage
multiply that percentage in decimal format by 255. Below
I multiplied 255 by .75 (75%) to arrive at 191.

R1(config-if)#dialer load-threshold 191 ?

either Threshold decision based on max of inbound and outbound traffic

inbound Threshold decision based on inbound traffic only

outbound Threshold decision based on outbound traffic only



R1(config-if)#dialer load-threshold 191 either

As illustrated by IOS Help in the above configuration
dialer load-threshold has additional options as well. You can configure the interface to consider only incoming
outgoing
or all traffic when calculating when to bring the next channel up.

Configuring Multilink PPP is just one of the skills you’ll need to earn your CCNA and pass the CCNP BCRAN exam. Don’t underestimate ISDN on Cisco’s certification exams!

To earn your Cisco CCNA certification and pass the BSCI CCNP exam
you have to know your protocol basics like the back of your hand! To help you review these important concepts
here's a quick look at the basics of RIPv1
RIPv2
IGRP
and EIGRP.

RIPv1: Broadcasts updates every 30 seconds to the address 255.255.255.255. RIPv1 is a classful protocol
and it does not recognize VLSM
nor does it carry subnet masking information in its routing updates. Update contains entire RIP routing table. Uses Bellman-Ford algorithm. Allows equal-cost load-balancing by default. Max hop count is 15. Does not support clear-text or MD5 authentication of routing updates. Updates carry 25 routes maximum.

RIPv2: Multicasts updates every 30 seconds to the address 224.0.0.9. RIPv2 is a classless protocol
allowing the use of subnet masks. Update contains entire RIP routing table. Uses Bellman-Ford algorithm. Allows equal-cost load-balancing by default. Max hop count is 15. Supports clear-text and MD5 authentication of routing updates. Updates carry 25 routes maximum.

IGRP: Broadcasts updates every 90 seconds to the address 255.255.255.255. IGRP is a Cisco-proprietary protocol
and is also a classful protocol and does not recognize subnet masking. Update contains entire routing table. Uses Bellman-Ford algorithm. Equal-cost load-balancing on by default; unequal-cost load-sharing can be used with the variance command. Max hop count is 100.

EIGRP: Multicasts full routing table only when an adjacency is first formed. Multicasts updates only when there is a change in the network topology
and then only advertises the change. Multicasts to 224.0.0.10 and allows the use of subnet masks. Uses DUAL routing algorithm. Unequal-cost load-sharing available with the variance command.

By mastering the basics of these protocols
you're laying the foundation for success in the exam room and when working on production networks. Pay attention to the details and the payoff is "CCNA" and "CCNP" behind your name!

Earning your Cisco CCNA and CCNP is a tough proposition
and part of that is the fact that you quickly learn that there’s usually more than one way to do things with Cisco routers – and while that’s generally a good thing
you better know the ins and outs of all options when it comes to test day and working on production networks. Working with Frame Relay subinterfaces and split horizon is just one such situation.

One reason for the use of subinterfaces is to circumvent the rule of split horizon. You recall from your CCNA studies that split horizon dictates that a route cannot be advertised out the same interface upon which it was learned in the first place. In the following example
R1 is the hub and R2 and R3 are the spokes. All three routers are using their physical interfaces for frame relay connectivity
and they are also running RIPv2 172.12.123.0 /24. Each router is also advertising a loopback interface
using the router number for each octet.

R1(config)#int s0

R1(config-if)#ip address 172.12.123.1 255.255.255.0

R1(config-if)#no frame inverse

R1(config-if)#frame map ip 172.12.123.2 122 broadcast

R1(config-if)#frame map ip 172.12.123.3 123 broadcast

R1(config-if)#no shut

R2(config)#int s0

R2(config-if)#encap frame

R2(config-if)#no frame inver

R2(config-if)#frame map ip 172.12.123.1 221 broadcast

R2(config-if)#frame map ip 172.12.123.3 221 broadcast

R2(config-if)#ip address 172.12.123.2 255.255.255.0

R3(config)#int s0

R3(config-if)#encap frame

R3(config-if)#no frame inver

R3(config-if)#frame map ip 172.12.123.1 321 broadcast

R3(config-if)#frame map ip 172.12.123.2 321 broadcast

R3(config-if)#ip address 172.12.123.3 255.255.255.0


R1#show ip route rip

2.0.0.0/32 is subnetted
1
subnets

R 2.2.2.2 [120/1] via 172.12.123.2
0
Serial0

3.0.0.0/32 is subnetted
1
subnets

R 3.3.3.3 [120/1] via 172.12.123.3
0
Serial0

R2#show ip route rip

1.0.0.0/32 is subnetted
1
subnets

R 1.1.1.1 [120/1] via 172.12.123.1
0
Serial0

R3#show ip route rip

1.0.0.0/32 is subnetted
1
subnets

R 1.1.1.1 [120/1] via 172.12.123.1
0
Serial0

The hub router R1 has a route to both loopbacks
but neither spoke has a route to the other spoke's loopback. That's because split horizon prevents R1 from advertising a network via Serial0 if the route was learned on Serial0 to begin with.

We've got two options here
one of which is to disable spilt horizon on the interface. While doing so will have the desired effect in our little network
disabling split horizon is not a good idea and should be avoided whenever possible. We’re not going to do it in this lab
but here is the syntax to do so:

R1(config)#interface serial0

R1(config-if)#no ip split-horizon

A better solution is to configure subinterfaces on R1. The IP addressing will have to be revisited
but that's no problem here. R1 and R2 will use 172.12.123.0 /24 to communicate
while R1 and R3 will use 172.12.13.0 /24. R3's serial0 interface will need to be renumbered
so let's look at all three router configurations:

R1(config)#interface serial0

R1(config-if)#encap frame

R1(config-if)#no frame inverse-arp

R1(config-if)#no ip address


R1(config-if)#interface serial0.12 multipoint

R1(config-subif)#ip address 172.12.123.1 255.255.255.0

R1(config-subif)#frame map ip 172.12.123.2 122 broadcast


R1(config-subif)#interface serial0.31 point-to-point

R1(config-subif)#ip address 172.12.13.1 255.255.255.0

R1(config-subif)#frame interface-dlci 123


R2(config)#int s0

R2(config-if)#ip address 172.12.123.2 255.255.255.0

R2(config-if)#encap frame

R2(config-if)#frame map ip 172.12.13.3 221 broadcast

R2(config-if)#frame map ip 172.12.123.1 221 broadcast

R3(config)#int s0

R3(config-if)#ip address 172.12.13.3 255.255.255.0

R3(config-if)#encap frame

R3(config-if)#frame map ip 172.12.13.1 321 broadcast

R3(config-if)#frame map ip 172.12.123.2 321 broadcast

A frame map statement always names the REMOTE IP address and the LOCAL DLCI. Don't forget the broadcast option!

Show frame map shows us that all the static mappings on R1 are up and running. Note the "static" output
which indicates these mappings are a result of using the frame map command. Pings are not shown
but all three routers can ping each other at this point.

R1#show frame map

Serial0 (up): ip 172.12.123.2 dlci 122(0x7A
0
static


broadcast
CISCO
status defined
active

Serial0 (up): ip 172.12.13.3 dlci 123(0x7B
0
static


broadcast
CISCO
status defined
active

After the 172.12.13.0 /24 network is added to R1 and R3’s RIP configuration
R2 and R3 now have each other's loopback network in their RIP routing tables.

R2#show ip route rip

1.0.0.0/32 is subnetted
1
subnets

R 1.1.1.1 [120/1] via 172.12.123.1
0
Serial0


3.0.0.0/32 is subnetted
1
subnets

R 3.3.3.3 [120/1] via 172.12.123.1
0
Serial0

R3#show ip route rip

1.0.0.0/32 is subnetted
1
subnets

R 1.1.1.1 [120/1] via 172.12.13.1
0
Serial0

2.0.0.0/32 is subnetted
1
subnets

R 2.2.2.2 [120/1] via 172.12.13.1
0
Serial0

While turning split horizon off is one way to achieve total IP connectivity
doing so can have other unintended results. The use of subinterfaces is a more effective way of allowing the spokes to see the hub's loopback network.

BECNs and FECNs aren't just important to know for your Cisco CCNA and CCNP certification exams - they're an important part of detecting congestion on a Frame Relay network and allowing the network to dynamically adjust its transmission rate when congestion is encountered.

The Forward Explicit Congestion Notification (FECN
pronounced "feckon") bit is set to zero by default
and will be set to 1 if congestion was experienced by the frame in the direction in which the frame was traveling. A DCE (frame relay switch) will set this bit
and a DTE (router) will receive it
and see that congestion was encountered along the frame's path.

If network congestion exists in the opposite direction in which the frame was traveling
the Backward Explicit Congestion Notification (BECN
pronounced "beckon") will be set to 1 by a DCE.

If this is your first time working with BECNs and FECNs
you might wonder why the BECN even exists - after all
why send a "backwards" notification? The BECN is actually the most important part of this entire process
since it's the BECN bit that indicates to the sender that it needs to slow down!

For example
frames sent from Kansas City to Green Bay encounter congestion in the FR cloud. A Frame Switch sets the FECN bit to 1. In order to alert KC that it's sending data too fast
GB will send return frames with the BECN bit set. When KC sees the BECN bit is set to 1
the KC router knows that the congestion occurred when frames were sent from KC to GB.

Frame Relay BECN Adaptive Shaping allows a router to dynamically throttle back on its transmission rate if it receives frames from the remote host with the BECN bit set. In this case
KC sees that the traffic it's sending to GB is encountering congestion
because the traffic coming back from GB has the BECN bit set. If BECN Adaptive Shaping is running on KC
that router will adjust to this congestion by slowing its transmission rate. When the BECNs stop coming in from GB
KC will begin to send at a faster rate.

BECN Adaptive Shaping is configured as follows:

KC(config)#int s0

KC(config-if)#frame-relay adaptive-shaping becn

To see how many frames are coming in and going out with the BECN and FECN bits set
run show frame pvc.

R3#show frame pvc

<>

input pkts 306 output pkts 609 in bytes 45566

out bytes 79364 dropped pkts 0 in FECN pkts 0

in BECN pkts 0 out FECN pkts 0 out BECN pkts 0

in DE pkts 0 out DE pkts 0

out bcast pkts 568 out bcast bytes 75128

pvc create time 01:26:27
last time pvc status changed 01:26:27

Just watch the "in"s and "out"s of BECN
FECN
and DE in both the exam room and your production networks!

Whether you're just starting to think about passing the CCNA or CCNP exams
or you've been on the certification track for a while
you've got to have a plan for success. If you wanted to drive your car from Florida to California
you'd create a plan to get there. You'd get a map and decide how far you wanted to drive per day
and maybe even make some hotel reservations in advance. You certainly wouldn't get in your car
just drive it randomly down the nearest highway
and hope you ended up in California
would you?

Certainly not. Earning your CCNA certification is the same way. It's not enough to just study a few minutes "when you feel like it"
or tell yourself that you'll start studying for the exams "when I get such-and-such done". The perfect time to start on the road to Cisco certification is not tomorrow
and it's not next week. It's today.

You're much better off with one hour of solid study than three hours of interrupted
unfocused study. Here are a few ways to go about getting the kind of quality study time that will get you to the CCNA or CCNP (or any Cisco certification
for that matter!).

Schedule your study time
and regard this study time as you would an appointment with a client. If you were to meet a customer at 10:00 to discuss a network install
would you just decide not to show up and watch television instead? Not if you wanted the job. The same goes for your study time. That's an appointment with the most important customer of all - YOU.

Turn your cell
iPod
TV
instant messenger
and all other electronic collars off for the duration of your study time. I know those of us in information technology don't like to say this
but we can actually exist without being in touch with the world for a little while. You may even get to like it! Having uninterrupted study time is key to CCNA and CCNP exam success.

Finally
schedule your exam before you start studying. Contrary to what many people think
deadline
is not a dirty word. We do our best work when we have a deadline and a schedule to keep. Make out your study schedule
schedule your exam
and get to work just as you would a network project for a customer. The project you're working on is your career and your life
and by following these simple steps you can make it a highly successful project - by passing your CCNA and CCNP exam!

A prime topic of your CCNA and CCNP CIT exams will be connecting Cisco routers directly via their Serial interfaces
and while the configuration is straightforward
there are some vital details and show commands you must know in order to pass the exams and configure this successfully in production and home lab networks. Let's take a look at a sample configuration.

Connecting Cisco routers directly via their Serial interfaces works really well once you get it running - and getting such a connection up and running is easy enough. You can use show controller serial x to find out which endpoint is acting as the DCE
and it's the DCE that must be configured with the clockrate command.

R3#show controller serial 1

HD unit 1
idb = 0x11B4DC
driver structure at 0x121868

buffer size 1524 HD unit 1
V.35 DCE cable

R3(config)#int serial1

R3(config-if)#ip address 172.12.13.3 255.255.255.0

R3(config-if)#clockrate 56000

R3(config-if)#no shut

Failure to configure the clockrate has some interesting effects regarding the physical and logical state of the interfaces. Let's remove the clockrate from R3 and see what happens.

R3(config)#int s1

R3(config-if)#no clockrate 56000

R3(config-if)#

18:02:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1
changed state to down

The line protocol doesn't drop immediately
but it does drop. Let's run show interface serial1 to compare the physical and logical interface states.

R3#show int serial1

Serial1 is up
line protocol is down

Physically
the interface is fine
so the physical interface is up. It's only the logical part of the interface - the line protocol - that is down. It's the same situation on R1.

R1#show inter serial1

Serial1 is up
line protocol is down

While a router misconfiguration is the most likely cause of a serial connection issue
that's not the only reason for clocking issues. Cisco's website documentation mentions CSU/DSU misconfiguration
out-of-spec cables
bad patch panel connections
and connecting too many cables together as other reasons for clocking problems. Still
the number one reason for clocking problems in my experience is simply forgetting to configure the clockrate command!

As a CCNA or CCNP
one thing you've got to get used to is that change is constant. Cisco regularly issues new IOS versions
not to mention the many different kinds of hardware they produce! While it's always nice to have "the latest and the greatest" when it comes to routers
switches
firewalls
etc.
we have to be prepared for the fact that not all our clients are going to have that latest and greatest!

For instance
there are still quite a few Catalyst 5000 switches out there humming away
and if you're used to working on IOS-driven switches like the 2950
the same command can have dramatically different results.

Let's say you're going to examine the spanning tree protocol (STP) setup of a new client. You're used to working with newer 2950 switches
and you've always run show span on those switches to display spanning-tree information. Then
you run show span on a Catalyst 5000 - and something like this shows:

switch (enable) show span

Destination : Port 6/1

Admin Source : Port 6/2

Oper Source : Port 6/2

Direction : transmit/receive

Incoming Packets: disabled

Learning : enabled

Multicast : enabled

Filter : -

Status : active

Total local span sessions: 1

What's going on here?

The command show span on a 5000 will not show spanning tree stats - instead
what you're going to see are statistics relating to Switched Port ANalyzer (SPAN). Surprise!

Consider an example where you're used to running show span on 5000 switches to see SPAN information. When you run that on a 2950
you know now what you're going to get - spanning tree information! On a 2950
you'll need to run show monitor session
followed by the SPAN session number.

SW1#show monitor session 1

Session 1

---------

Type : Local Session

Source Ports :

Both : Fa0/1

Destination Ports : Fa0/2

Encapsulation : Native

Ingress: Disabled

As a CCNA and CCNP
this is one of those things you just have to get used to. Commands are going to be different
sometimes radically so
between models. That's why you need to be adept with both IOS Help and Cisco's online documentation site. IOS Help is easy
but the online doc site take a little getting used to. Once you learn how to navigate that site
a world of Cisco knowledge is at your fingertips.

Besides
when you sit for the CCIE lab exam
that will be the only friend you have! And a valuable friend it can be - you're just going to have to trust me on that one. :)

When you're studying to pass the Cisco CCNA and CCNP certification exams
you quickly learn that there's always something else to learn. (You'll really pick up on this in your CCIE studies
trust me!) Today we'll take a look at an often-overlooked topic in Frame Relay
the encapsulation type. You don't exactly change this on a daily basis in production networks (not if you want to stay employed
anyway!)
but it's an important exam topic that you must be familiar with.

The DCE and DTE must agree on the LMI type
but there's another value that must be agreed upon by the two DTEs serving as the endpoints of the VC. The Frame encapsulation can be left at the default of Cisco (which is Cisco-proprietary)
or it can be changed to the industry-standard IETF
as shown below. If a non-Cisco router is the remote endpoint
IETF encapsulation must be used. Note that the default of Cisco isn't listed as an option by IOS Help
so you better know that one by heart!

R1(config)#int s0

R1(config-if)#encap frame ?

ietf Use RFC1490/RFC2427 encapsulation



R1(config-if)#encap frame ietf

What if a physical interface is in use and some remote hosts require Cisco encapsulation and others require IETF? The encapsulation type can be configured on a per-PVC basis as well. One encap type can be used on the interface
and any map statements that require a different encap type can have that specified in the appropriate map statement. In the following example
all PVCs will use the default Cisco encapsulation type except for PVC 115. The frame map statement using that PVC has ietf specified.

R1(config)#int s0/0

R1(config-if)#encap frame

R1(config-if)#frame map ip 172.12.123.3 123 broadcast

R1(config-if)#frame map ip 172.12.123.2 122 ietf broadcast

show frame map shows us that the mapping to DLCI 123 is using Cisco encapsulation
and DLCI 122 is using IETF.

R1#show frame map

Serial0 (up): ip 172.12.123.3 dlci 123(0x7B
0
static

broadcast
CISCO
status defined
active

Serial0 (up): ip 172.12.123.2 dlci 122(0x7B
0
static

broadcast
ietf
status defined
active

Just remember that Cisco is the default
and all PVCs will use Cisco unless you specify IETF in the frame map statement itself. You could also change the entire interface to use IETF for all mappings with the frame-relay encapsulation IETF command. For Cisco exams
as well as work on production networks
it's always a good idea to know more than one way to do something!

As a CCNA and/or CCNP candidate
you've got to be able to spot situations where Cisco router features can save your client money and time. For example
if a spoke router is calling a hub router and the toll charges at the spoke site are higher than that of the hub router
having the hub router hang up initially and then call the spoke router back can save the client money (and make you look good!)

A popular method of doing this is using PPP callback
but as we all know
it's a good idea to know more than one way to do things in Cisco World! A lesser-known but still effective method of callback is Caller ID Screening & Callback. Before we look at the callback feature
though
we need to know what Caller ID Screening is in the first place!

This feature is often referred to simply as "Caller ID"
which can be a little misleading if you've never seen this service in operation before. To most of us
Caller ID is a phone service that displays the source phone number of an incoming call. Caller ID Screening has a different meaning
though. Caller ID Screening on a Cisco router is really another kind of password - it defines the phone numbers that are allowed to call the router.

The list of acceptable source phone numbers is created with the isdn caller command. Luckily for us
this command allows the use of x to specify a wildcard number. The command isdn caller 555xxxx results in calls being accepted from any 7-digit phone number beginning with 555
and rejected in all other cases. We'll configure R2 to do just that and then send a ping from R1 to R2. To see the results of the Caller ID Screening
debug dialer will be run on R1 before sending the ping. I’ve edited this output
since the output you see here will be repeated fire times – once for each ping packet.

R2(config-if)#isdn caller 555xxxx

R1#debug dialer

Dial on demand events debugging is on

R1#ping 172.12.12.2

Type escape sequence to abort.

Sending 5
100
ICMP Echos to 172.12.12.2
timeout is 2 seconds:

03:30:25: BR0 DDR: Dialing cause ip (s=172.12.12.1
d=172.12.12.2)

03:30:25: BR0 DDR: Attempting to dial 8358662.

Success rate is 0 percent (0/5)


R1 doesn't give us any hints as to what the problem is
but we can see that the pings definitely aren't going through. On R2
show dialer displays the number of screened calls.

R2#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last DNIS Last status

8358661 1 0 00:03:16 successful

7 incoming call(s) have been screened.

0 incoming call(s) rejected for callback.

The callback option mentioned in the last line shown above enables the router to reject a phone call
and then call that router back seconds later.

R2 will now be configured to initially hang up on R1
and then call R1 back.

R2(config-if)#isdn caller 8358661 callback

R1 will now ping R2. The pings aren't returned
but seconds later R2 calls R1 back.

R1#ping 172.12.12.2

Success rate is 0 percent (0/5)

R1#

03:48:12: BRI0: wait for isdn carrier timeout
call id=0x8023

R1#

03:48:18: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up

R1#

03:48:18: BR0:1 DDR: dialer protocol up

R1#

03:48:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1
changed state to up

R1#

03:48:24: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 8358662 R2

show dialer on R2 shows the reason for the call to R1 is a callback return call.

R2#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last DNIS Last status

8358661 3 0 00:00:48 successful

7 incoming call(s) have been screened.

10 incoming call(s) rejected for callback.

BRI0:1 - dialer type = ISDN

Idle timer (120 secs)
Fast idle timer (20 secs)

Wait for carrier (30 secs)
Re-enable (15 secs)

Dialer state is data link layer up

Dial reason: Callback return call

Time until disconnect 71 secs

Connected to 8358661 (R1)

The drawback to Caller ID Callback is that not all telco switches support it
so if you have the choice between this and PPP Callback
you're probably better off with PPP Callback. However
it's always a good idea to know more than one way to get things done with Cisco!

More CCNA and CCNP candidates than ever before are putting together their own home labs
and there's no better way to learn about Cisco technologies than working with the real thing. Getting the routers and switches is just part of putting together a great CCNA / CCNP home lab
though. You've got to get the right cables to connect the devices
and this is an important part of your education as well. After all
without the right cables
client networks are going to have a hard time working!

For your Cisco home lab
one important cable is the DTE/DCE cable. These cables have two major uses in a home lab. To practice directly connecting Cisco routers via Serial interfaces (an important CCNA skill)
you'll need to connect them with a DTE/DCE cable. Second
if you plan on having a Cisco router act as a frame relay switch in your lab
you'll need multiple DTE/DCE cables to do so. (Visit my website's Home Lab Help section for a sample Frame Relay switch configuration.)

If you have multiple switches in your lab
that's great
because you'll be able to get a lot of spanning tree protocol (STP) work in as well as creating Etherchannels. To connect your switches
you'll need crossover cables.

You'll need some straight-through cables as well to connect your routers to the switches.

Finally
if you're lucky enough to have an access server as part of your lab
you'll need an octal cable to connect your AS to the other routers and switches in your lab. The octal cable has one large connector on one end and eight numbered RJ-45 connectors on the other end. The large connector should be attached to the async port on your AS
and the numbered RJ-45 connectors will be connected to the console ports on your other routers and switches.

Choosing and connecting the right cables for your Cisco CCNA / CCNP home lab is a great learning experience
and it's also an important part of your Cisco education. After all
all great networks and home labs all begin at Layer One of the OSI model!

CCNA and CCNP candidates are well-versed in Spanning-Tree Protocol
and one of the great things about STP is that it works well with little or no additional configuration. There is one situation where STP works against us just a bit while it prevents switching loops
and that is the situation where two switches have multiple physical connections.

You would think that if you have two separate physical connections between two switches
twice as much data could be sent from one switch to the other than if there was only one connection. STP doesn't allow this by default
however in an effort to prevent switching loops from forming
one of the paths will be blocked.

SW1 and SW2 are connected via two separate physical connections
on ports fast0/11 and fast 0/12. As we can see here on SW1
only port 0/11 is actually forwarding traffic. STP has put the other port into blocking mode (BLK).


SW1#show spanning vlan 10


(some output removed for clarity)


Interface Role Sts Cost Prio.Nbr Type


Fa0/11 Root FWD 19 128.11 P2p

Fa0/12 Altn BLK 19 128.12 P2p


While STP is helping us by preventing switching loops
STP is also hurting us by preventing us from using a perfectly valid path between SW1 and SW2. We could literally double the bandwidth available between the two switches if we could use that path that is currently being blocked.

The secret to using the currently blocked path is configuring an Etherchannel. An Etherchannel is simply a logical bundling of 2 - 8 physical connections between two Cisco switches.

Configuring an Etherchannel is actually quite simple. Use the command "channel-group 1 mode on" on every port you want to be placed into the Etherchannel. Of course
this must be done on both switches if you configure an Etherchannel on one switch and don't do so on the correct ports on the other switch
the line protocol will go down and stay there.

The beauty of an Etherchannel is that STP sees the Etherchannel as one connection. If any of the physical connections inside the Etherchannel go down
STP does not see this
and STP will not recalculate. While traffic flow between the two switches will obviously be slowed
the delay in transmission caused by an STP recalculation is avoided. An Etherchannel also allows us to use multiple physical connections at one time.

Here's how to put these ports into an Etherchannel:

SW1#conf t

Enter configuration commands
one per line. End with CNTL/Z.

SW1(config)#interface fast 0/11

SW1(config-if)#channel-group 1 mode on

Creating a port-channel interface Port-channel 1


SW1(config-if)#interface fast 0/12

SW1(config-if)#channel-group 1 mode on



SW2#conf t

Enter configuration commands
one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#channel-group 1 mode on

SW2(config-if)#int fast 0/12

SW2(config-if)#channel-group 1 mode on


The command "show interface trunk" and "show spanning-tree vlan 10" will be used to verify the Etherchannel configuration.


SW2#show interface trunk (some output removed for clarity)


Port Mode Encapsulation Status Native vlan

Po1 desirable 802.1q trunking 1


SW2#show spanning vlan 10 (some output removed for clarity)


Interface Role Sts Cost Prio.Nbr Type


Po1 Desg FWD 12 128.65 P2p


Before configuring the Etherchannel
we saw individual ports here. Now we see "Po1"
which stands for the interface "port-channel1". This is the logical interface created when an Etherchannel is built. We are now using both physical paths between the two switches at one time!

That's one major benefit in action let's see another. Ordinarily
if the single open path between two trunking switches goes down
there is a significant delay while another valid path is opened - close to a minute in some situations. We will now shut down port 0/11 on SW2 and see the effect on the etherchannel.

SW2#conf t

Enter configuration commands
one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#shutdown

3w0d: %LINK-5-CHANGED: Interface FastEthernet0/11
changed
state to administratively down


SW2#show spanning vlan 10


VLAN0010

Spanning tree enabled protocol ieee

Interface Role Sts Cost Prio.Nbr Type


Po1 Desg FWD 19 128.65 P2p



SW2#show interface trunk


Port Mode Encapsulation Status Native vlan


Po1 desirable 802.1q trunking 1

The Etherchannel did not go down! STP sees the Etherchannel as a single link therefore
as far as STP is concerned
nothing happened.

Building an Etherchannel and knowing how it can benefit your network is an essential skill for CCNA and CCNP success
and it comes in very handy on the job as well. Make sure you are comfortable with building one before taking Cisco's exams!

To pass the Cisco CCNA and CCNP certification exams
as well as becoming a world-class networker
you've got to know how and when to use floating static routes. And if you're wondering what makes them "float" -- read on!

In this example
R1 and R2 are running OSPF over a Frame Relay network
172.12
/24. They're also connected by a BRI ISDN link
172.12
/24. R1 is advertising a loopback network
1.1
/32
via OSPF. We want R2 to have a route to that loopback even if the frame goes down - and here
we'll use a floating static route to make that happen.

R2 sees the route to the loopback interface via OSPF
and can ping that interface successfully.

R2#show ip route ospf

1.0.0.0/32 is subnetted
1
subnets

O 1.1.1.1 [110/65] via 172.12.123.1
0
Serial0


R2#ping 1.1.1.1

Type escape sequence to abort.

Sending 5
100
ICMP Echos to 1.1.1.1
timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5)
round-trip min/avg/max = 68/68/68 ms

This is when it's important to know your administrative distances.... or at least know where to look to see them! The AD of OSPF is 110
which means we can configure a static route to 1.1.1.1 /32
and as long as the AD of the static route is higher than 110
it won't be used unless the OSPF route leaves the routing table. That's why this kind of route is called a "floating" static route - the route "floats" in the routing table and isn't seen unless the primary route leaves the table.

You learned how to write a static route in your CCNA studies
but you also remember that the default AD of a static route is either 1 or 0... and both of those values are less than 110! To change the AD of a static route
configure the desired distance at the end of the ip route command.

R2(config)#ip route 1.1.1.1 255.255.255.255 bri0 ?

<1-255> Distance metric for this route

A.B.C.D Forwarding router's address

name Specify name of the next hop

permanent permanent route

tag Set tag for this route


R2(config)#ip route 1.1.1.1 255.255.255.255 bri0 111

The static route has an AD that's only one higher than that of the OSPF route
but that's enough to make the route "float" and not yet be seen in the routing table.

R2#show ip route

1.0.0.0/32 is subnetted
1
subnets

O 1.1.1.1 [110/65] via 172.12.123.1
0
Serial0

172.12.0.0/24 is subnetted
2
subnets

C 172.12.12.0 is directly connected
BRI0

C 172.12.123.0 is directly connected
Serial0

Let's see the effect on the routing table when the Serial0 interface is closed.

R2(config)#int s0

R2(config-if)#shutdown


12:04:53: %OSPF-5-ADJCHG: Process 1
Nbr 172.12.123.1 on Serial0 from FULL to DOWN
Neighbor Down: Interface down or detached


12:04:55: %SYS-5-CONFIG_I: Configured from console by console

12:04:55: %LINK-5-CHANGED: Interface Serial0
changed state to administratively down


12:04:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0
changed state to down


R2#show ip route

1.0.0.0/32 is subnetted
1
subnets

S 1.1.1.1 is directly connected
BRI0

172.12.0.0/24 is subnetted
1
subnets

C 172.12.12.0 is directly connected
BRI0

The floating static route appears in the table
but the ISDN link will not come up until the BRI interface has traffic to send. Let's ping 1.1.1.1 and see what happens. debug dialer was configured on R2 before sending the ping.

R2#ping 1.1.1.1

Type escape sequence to abort.

Sending 5
100
ICMP Echos to 1.1.1.1
timeout is 2 seconds:

12:16:01: BR0 DDR: Dialing cause ip (s=172.12.12.2
d=1.1.1.1)

12:16:01: BR0 DDR: Attempting to dial 8358661

12:16:01: %LINK-3-UPDOWN: Interface BRI0:1
changed state to up.!!

12:16:01: BR0:1 DDR: dialer protocol up!!

Success rate is 80 percent (4/5)
round-trip min/avg/max = 36/37/40 ms

The link comes up and traffic can still reach 1.1.1.1. Once R2 becomes an OSPF neighbor of R1 again
the OSPF route will again become the primary path and the floating static route leaves the routing table.

R2(config)#int s0

R2(config-if)#no shut

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

172.12.123.1 1 FULL/DR 00:01:57 172.12.123.1 Serial0


R2#show ip route

1.0.0.0/32 is subnetted
1
subnets

O 1.1.1.1 [110/65] via 172.12.123.1
0
Serial0

172.12.0.0/24 is subnetted
2
subnets

C 172.12.12.0 is directly connected
BRI0

C 172.12.123.0 is directly connected
Serial0

A floating static route is an excellent "back door" that will keep the ISDN link down while allowing that link to serve as a backup route. Just make sure the ISDN link comes down when you expect it to - always check that with show isdn status!

I was reading The Big Moo: Stop Trying To Be Perfect and Start Being Remarkable this morning
and I’d recommend a copy of this to anyone who wants to improve their career and their future. And that’s all of us
right?


There was one particular line that really stood out to me: Betting on change is always the safest bet available. That describes life perfectly
but it also describes a career in Information Technology perfectly as well. There is no field in the world that has the constant and never-ending changes that IT does. And every single one of us can look at this as a massive opportunity for personal and professional growth.


Is that how you’re looking at it? I remember when I passed my first certification exam
the Novell CAN
back in 1997. Man
I thought I knew it all then! But I quickly learned that you’ve got to keep learning in IT. I also learned that if you’re willing to put in the work and make the sacrifices
there’s no other field with the limitless potential for growth and excellence.


Like everyone else
my career has had its ups and downs
but I always kept learning and growing. Today
I’ve got my dream job
working with studI was reading The Big Moo: Stop Trying To Be Perfect and Start Being Remarkable this morning
and I’d recommend a copy of this to anyone who wants to improve their career and their future. And that’s all of us
right?


There was one particular line that really stood out to me: Betting on change is always the safest bet available. That describes life perfectly
but it also describes a career in Information Technology perfectly as well. There is no field in the world that has the constant and never-ending changes that IT does. And every single one of us can look at this as a massive opportunity for personal and professional growth.


Is that how you’re looking at it? I remember when I passed my first certification exam
the Novell CAN
back in 1997. Man
I thought I knew it all then! But I quickly learned that you’ve got to keep learning in IT. I also learned that if you’re willing to put in the work and make the sacrifices
there’s no other field with the limitless potential for growth and excellence.


Like everyone else
my career has had its ups and downs
but I always kept learning and growing. Today
I’ve got my dream job
working with students and customers just like you – to help you create your own future.


The next 18 months are filled with endless possibilities
particularly with the rapid growth of VoIP and Microsoft Vista on the horizon. There will be those who rationalize their inertia
saying “I’ll never have to support those
so I don’t need to learn them."


There will also be those who see VoIP and Vista as enormous opportunities to learn and advance in their careers and their lives. These people will get started today
learning the fundamentals of Cisco and advancing their networking knowledge in order to be ready for opportunities as they come along.


You can’t start studying and learning when the opportunity arrives – you’ve got to be ready when opportunity knocks. If you’ve been putting off studying for a Cisco or other computer certification – and I know the summer is a really good time for putting off studying – get back on track today.


Because you never know what opportunities are going to come along – but you do know that when they do
you’ve got to be ready to take advantage. After all
opportunity really does knock only once!
ents and customers just like you – to help you create your own future.


The next 18 months are filled with endless possibilities
particularly with the rapid growth of VoIP and Microsoft Vista on the horizon. There will be those who rationalize their inertia
saying “I’ll never have to support those
so I don’t need to learn them."


There will also be those who see VoIP and Vista as enormous opportunities to learn and advance in their careers and their lives. These people will get started today
learning the fundamentals of Cisco and advancing their networking knowledge in order to be ready for opportunities as they come along.


You can’t start studying and learning when the opportunity arrives – you’ve got to be ready when opportunity knocks. If you’ve been putting off studying for a Cisco or other computer certification – and I know the summer is a really good time for putting off studying – get back on track today.


Because you never know what opportunities are going to come along – but you do know that when they do
you’ve got to be ready to take advantage. After all
opportunity really does knock only once!

Planning for success on the CCNA
CCNP
and other Cisco exams is much like taking a trip in your car. You've got to plan ahead
accept the occasional detour
and just keep on going until you get there. But what do you do before you get started?

Create a road map - for success.

If you were driving from one side of the country to another
you certainly wouldn't just get in your car and start driving
would you? No. You would plan the trip out ahead of time. What would happen if you just got in the car and started driving in the hope that you would someday arrive at your final destination? You would never get there
and you'd spend a lot of time wandering aimlessly.

Don't spend your study time and slow your progress by studying for a Cisco exam without planning the trip. Schedule your study time as you would an appointment with a client
and keep that appointment. Make sure that your study time is quality study - turn your TV
iPod
and cell off. If you hit a bump in the road and don't get your certification the first time you take the exam
regroup and create another plan. Study until you get to the point that on exam day
you know that you are already a CCNA or CCNP and you’re just there at the testing center to make it official.

The journey to success is not a straight line. When you look at a chart that shows a company's financial progress
the line never goes straight up. there are some ups and downs
but the overall result is success. The path to your eventual career and certification exam success may not be a direct one
but the important part is to get started - and to get any journey started
you've got to create a road map for a successful arrival at your destination.

* What kinds of certifications should I consider for a PC Specialist career?

As a PC Specialist
people will rely on your specialized computer training and skills to keep the office running smoothly. You must have the following certifications:

• PC Specialist Certificate
• Microsoft Certified Systems Engineer
• Microsoft Certified Professional

* What kinds of certifications should I consider for a Software Engineer career?

The software engineer designs and develops systems to control and automate manufacturing
business
or management processes. To obtain a position as a Software Engineer
you must have:

• A four-year degree in a computer-related discipline is required for most software engineering positions.

• Certification in various software applications is suggested.

• Training programs are available at community colleges
vocational schools
technical institutes and in the Armed Forces.

Earning and maintaining computer certification is a good way for software engineers to keep their skills up to date. In addition to Microsoft
Novell
Cisco and other high-tech companies
the Institute of Electrical and Electronics Engineers (IEEE) Computer Society offers relevant computer certifications.

* What kinds of certifications should I consider for a Systems Analyst career?

These workers figure out how to use computers to get things done. They tell businesses and other organizations which computers and software to buy
and they decide how to get those tools to work together. To qualify on this position
you must have:

• A four-year college degree in computer science
information science
or management information systems.

• Microsoft Certification and Microsoft Certified Professional (MCP)

* What kinds of certifications should I consider for a Systems Engineer career?

Systems engineering is like putting together a puzzle
matching varied pieces together to make one cohesive whole. Here are some certifications you need to comply:

• BS in systems engineering or other related engineering discipline or an equivalent combination of education and work related experience.

• Novell certifications

Earning computer certification at a prestigious educational institution is impressive. But
if you don't have that kind of money
you may take computer certification training courses anywhere and anyway you wish and then pay to take the exams. Passing the exams is what earns computer certification.

* What kinds of certifications should I consider for a Technical Instructor career?

As a technical instructor
you need to be mature and very oriented towards people. To be considered
you must have the following certifications:

• A four-year degree in a computer-related discipline is required for most software engineering positions.

• CompTIA’s Certified Technical Trainer (CTT+) certification.

* What kinds of certifications should I consider for a Wireless Specialist career?

Career certification programs are critical for aspiring Wireless Specialists. Many are looking for programs that have a complete engineering curriculum that concentrates entirely on wireless application. Some of these are the following:

• Certified Wireless Professional includes application for wireless development
its networking elements and security
and embedded systems. Number of hours needed to complete the certification depends on the institution offering the program
but in most cases these certifications requires minimum of 200 hours lecture in class room and an average of 200 hours in laboratory practice.

• Cisco Security Professional Design Certifications merely concentrates on the perimeter security of the data in the web site
largely to avoid being hacked. Different versions of Web security courses such as DVS 1.0 and DPS 1.0 are available for reference.

* What does certified mean?

There are four accepted meanings of the adjective “certified” but only two of which satisfy the needed meaning. To be certified means to be endorsed with authority by an institution or a person with higher position after one successfully meets certain requirements. Another meaning is that a person is qualified to do a certain job as supported by an appropriate document better known and regarded as a Certification.


* What certifications are there?

If you are pertaining to online certifications
there are lots to be traced. To help you find one best certification that fits your ability and interest
you may log on to reliable sites in the internet. For now
the following are the basic IT certifications:

• IT Auditing
• Document Imaging
• E-Commerce
• Internet/Intranet
• Linux
• Networking
• Printing
• Project Management
• IT Security
• Servers
• Service Technician
• Technical Trainer
• Webmaster


* Who benefits from certification?

Primarily the one given a certification benefits more. Being certified means one can properly function on a certain job. This means
companies will easily hire a person with certification especially when certifications come from a reliable learning institution.

In some ways
the company to which a certified person intends to apply for work will also benefit since the performance of the applying employee is being supported with a certification.


* Is certification better than experience?

The answer for that is a big "No." Certification means training. It is impossible for a person to send himself training without experiencing what it is he intends to do. For this reason
we cannot equate certification from experience since they do not share the same purpose. However
if you already have work experience
a certification is a big help for promotion
recognition and pay raises.

On the other hand
companies are not solely after experience but after educational attainments and performances. In other words
having completed a course as proved by a certification is a chance to be hired.


* Which certification program is best for me?

The best certification program for you is the one that fits your interests and capabilities. Those two factors should be considered above all ese when finding the right and best certification program for you.


* How much will getting certified cost?

Almost all training packages from different training institutions are cost effective. The training cost will depend on the training you want to pursue and in which training institution you intend to enroll. Generally
a trainee should prepare to pay between $100 and $400 for each training program.


* How long will certification take?

There are training institutions that offer a 6-month online training program. The usual training timeframe is one year. This length of training may exceed to a maximum of 2 years depending on the program conducted.


* Do I need a college degree to be certified?

You do not need a college degree to be certified. Some certification programs require one to have at least finished high school upon enrolling in a certain course.


* Will certification really help my career?

A certification may help your career. Nowadays
competition in the jobs is getting tougher. For one to stay in his or her job or to be promoted to a higher position
one factor to consider is his or her educational achievements. That is one reason why mastering your field of work by means of studying and training can be a great boost for your career. That is where a certification program can make or break your career advancement.


* Will I have to go somewhere for my certification training?

While you can find local institutions where you can take classes and tests
most training is done online now. You do not need to go somewhere else for your training. You do not even need to attend classes personally for your lessons. Not only is training done mostly online now
but examinations for certification are also given online.

Like TCP
BGP is connection-oriented. An underlying connection between two BGP speakers is established before any routing information is exchanged. This connection takes place on TCP port 179. As with EIGRP and OSPF
keepalive messages are sent out by the BGP speakers in order to keep this relationship alive.

Once the connection is established
the BGP speakers exchange routes and synchronize their tables. After this initial exchange
a BGP speaker will only send further updates upon a change in the network topology.

The IGP protocols that use Autonomous Systems
IGRP and EIGRP
require prospective neighbors to be in the same AS. This is not true with BGP. Routers can be in different Autonomous Systems and still exchange routes. The BGP neighbors do not have to be directly connected
and often are not
but do need to be able to reach the IP addresses they use in their neighbor statements.

A BGP peer that is in the same AS is referred to as an Internal BGP (iBGP) Peer
where a BGP peer in another AS is an External BGP (eBGP) Peer.

A sample iBGP configuration:

Router bgp 100

Neighbor 10.1.1.2 remote-as 100


A sample eBGP configuration:

Router bgp 100

Neighbor 10.1.1.2 remote-as 200

Cisco recommends that eBGP peers be directly connected
where iBGP peers generally will not be.

Before we get too much farther into BGP theory
let’s get a configuration started. You’ll use the router bgp command to configure a router as a BGP speaker. Right after that
the neighbor command will be used to identify this BGP speaker’s potential neighbors. (The terms "peer" and "neighbor" are interchangeable in BGP
but it's the neighbor statement that is used to statically define neighbors. BGP is not capable of discovering neighbors dynamically.)

R1(config-router)#neighbor 172.12.123.3 remote-as 200

While almost all of the neighbor options are just that -- optional -- you do have to specify the BGP AS of the remote router. BGP has no mechanism to dynamically discover neighbors. Remember
BGP speakers do not have to be in the same AS to become peers. To verify that the remote BGP speaker has become a peer
run show ip bgp neighbor.


R1#show ip bgp neighbor

BGP neighbor is 172.12.123.3
remote AS 200
external link

BGP version 4
remote router ID 0.0.0.0

BGP state = Active

Last read 00:01:39
hold time is 180
keepalive interval is 60 seconds

Received 0 messages
0
notifications
0
in queue

Sent 0 messages
0
notifications
0
in queue

Route refresh request: received 0
sent 0

Default minimum time between advertisement runs is 30 seconds

The output here can be a little misleading the first time you read it. The first highlighted line shows 172.12.123.3 is a BGP neighbor
is located in AS 200
and is an external link
indicating that the neighbor is in another AS entirely. The second highlighted line shows the BGP state as Active. This sounds great
but it actually means that a BGP peer connection does not yet exist with the prospective neighbor.

So even though the show ip bgp neighbor output indicated that this is an Active neighbor relationship
that’s not as good as it sounds. Of course
the reason the peer relationship hasn’t been established is that we haven’t configured R3 yet!


R3(config)#router bgp 200
R3(config-router)#neighbor 172.12.123.1 remote-as 100

Verify the peer establishment with show ip bgp neighbor:

R3#show ip bgp neighbor

BGP neighbor is 172.12.123.1
remote AS 100
external link

BGP version 4
remote router ID 172.12.123.1

BGP state = Established
up for 00:01:18

Last read 00:00:17
hold time is 180
keepalive interval is 60 seconds

Local host: 172.12.123.3
Local port: 179 (BGP uses TCP Port 179)

Foreign host: 172.12.123.1
Foreign port: 11007
The peer relationship between R1 and R3 has been established.

Now that you know how the neighbor relationship itself is built
you need to start learning the many options of the neighbor command. You’ll have to master these to become a CCNP and CCIE!

Passing the BSCI exam and earning your CCNP is all about knowing the details
and when it comes to EIGRP SIA routes
there are plenty of details to know. A quick check in a search engine for "troubleshoot SIA" will bring up quite a few matches. Troubleshooting SIA routes is very challengin in that there's no one reason they occur.

View the EIGRP topology table with the show ip eigrp topology command
and you'll see a code next to every successor and feasible successor. A popular misconception is that we want these routes to have an "A" next to them - so they're active. That's what we want
right? Active routes sound good
right?

Well
they sound good
but they're not. If a route shows as Active in the EIGRP topology table
that means that DUAL is currently calculating that route
and it's currently unusable. When a route is Passive ("P)
that means it's not being recalculated and it's a usable route.

Generally
a route shown as Active is going to be there for a very short period of time by the time you repeat the command
hopefully that Active route has gone Passive. Sometimes that doesn't happen
though
and the route becomes SIA - Stuck In Active.

A route becomes SIA when a query goes unanswered for so long that the neighbor relationship is reset. From experience
I can tell you that troubleshooting SIA routes is more of an art form than a science
but there are four main reasons a route becomes SIA:

The link is unidirectional
so the query can't possibly be answered.

The queried router's resources are unavailable
generally due to high CPU utilization.

The queried router's memory is corrupt or otherwise unable to allow the router to answer the query.

The link between the two routers is of low quality
allowing just enough packets through to keep the neighbor relationship intact
but not good enough to allow the replies through.

To sum it up
routes generally become SIA when a neighbor either doesn't answer a query
or either the query or reply took a wrong turn somewhere. I told you it wasn't the easiest thing to troubleshoot!

When you're working on your BCMSN exam on your way to CCNP certification
you'll read at length about how Cisco routers and multilayer switches can work to provide router redundancy - but there's another helpful service
Server Load Balancing
that does the same for servers. While HSRP
VRRP
and CLBP all represent multiple physical routers to hosts as a single virtual router
SLB represents multiple physical servers to hosts as a single virtual server.

In the following example
three physical servers have been placed into the SRB group ServFarm. They're represented to the hosts as the virtual server 210.1.1.14.

The hosts will seek to communicate with the server at 210.1.1.14
not knowing that they're actually communicating with the routers in ServFarm. This allows quick cutover if one of the physical servers goes down
and also serves to hide the actual IP addresses of the servers in ServFarm.

The basic operations of SLB involves creating the server farm
followed by creating the virtual server. We'll first add 210.1.1.11 to the server farm:

MLS(config)# ip slb serverfarm ServFarm

MLS(config-slb-sfarm)# real 210.1.1.11

MLS(config-slb-real)# inservice

The first command creates the server farm
with the real command specifying the IP address of the real server. The inservice command is required by SLB to consider the server as ready to handle the server farm's workload. The real and inservice commands should be repeated for each server in the server farm.

To create the virtual server:

MLS(config)# ip slb vserver VIRTUAL_SERVER

MLS(config-slb-vserver)# serverfarm ServFarm

MLS(config-slb-vserver)# virtual 210.1.1.14

MLS(config-slb-vserver)# inservice

From the top down
the vserver was named VIRTUAL_SERVER
which represents the server farm ServFarm. The virtual server is assigned the IP address 210.1.1.14
and connections are allowed once the inservice command is applied.

You may also want to control which of your network hosts can connect to the virtual server. If hosts or subnets are named with the client command
those will be the only clients that can connect to the virtual server. Note that this command uses wildcard masks. The following configuration would allow only the hosts on the subnet 210.1.1.0 /24 to connect to the virtual server.

MLS(config-slb-vserver)# client 210.1.1.0 0.0.0.255

SLB is the server end's answer to HSRP
VRRP
and GLBP - but you still need to know it to become a CCNP! Knowing redundancy strategies and protocols is vital in today's networks
so make sure you're comfortable with SLB before taking on the exam.

To pass the CCNP exams
you’ve got to master Quality of Service
and the first step in doing so is knowing the differences between the different QoS types.

Now this being Cisco
we can't just have one kind of QoS! We've got best-effort delivery
Integrated Services
and Differentiated Services. Let's take a quick look at all three.

Best-effort is just what it sounds like - routers and switches making their "best effort" to deliver data. This is considered QoS
but it's kind of a "default QoS". Best effort is strictly "first in
first out" (FIFO).

An entire path from Point A to Point B will be defined in advance when Integrated Services are in effect. Integrated Services is much like the High-Occupancy Vehicle lanes found in many larger cities. If your car has three or more people in it
you're considered a "priority vehicle" and you can drive in a special lane with much less congestion than regular lanes. Integrated Services will create this lane in advance for "priority traffic"
and when that traffic comes along
the path already exists. Integrated Services uses the Resource Reservation Protocol (RSVP) to create these paths. RSVP guarantees a quality rate of service
since this "priority path" is created in advance.

Integrated Services is defined in RFC 1613. Use your favorite search engine to locate a copy online and read more about this topic. It's a good idea to get into the habit of reading RFCs!

Of course
if you've got a lot of different dedicated paths being created that may or not be used very often
that's a lot of wasted bandwidth. That leads us to the third QoS model
the Differentiated Services model. Generally referred to as DiffServ
there are no advance path reservations and there's no RSVP. The QoS policies are written on the routers and switches
and they take action dynamically as needed. Since each router and switch can have a different QoS policy
DiffServ takes effect on a per-hop basis rather than the per-flow basis of Integrated Services. A packet can be considered "high priority" by one router and "normal priority" by the next.

Believe me
this is just the beginning when it comes to Quality of Service. It's a huge topic on your exams and in the real world's production networks
and as with all other Cisco topics
just master the fundamentals and build from there - and you're on your way to CCNP exam success!

To earn your CCNP certification and pass the BCMSN exam
you've got to know what HSRP does and the many configurable options. While the operation of HSRP is quite simple (and covered in a previous tutorial)
you also need to know how HSRP arrives at the MAC address for the virtual router - as well as how to configure a new MAC for this virtual router. This puts us in the unusual position of creating a physical address for a router that doesn't exist!

The output of show standby for a two-router HSRP configuration is shown below.

R2#show standby

Ethernet0 - Group 5

Local state is Standby
priority 100

Hellotime 3 sec
holdtime 10 sec

Next hello sent in 0.776

Virtual IP address is 172.12.23.10 configured

Active router is 172.12.23.3
priority 100 expires in 9.568

Standby router is local

1 state changes
last state change 00:00:22

R3#show standby

Ethernet0 - Group 5

Local state is Active
priority 100

Hellotime 3 sec
holdtime 10 sec

Next hello sent in 2.592

Virtual IP address is 172.12.23.10 configured

Active router is local

Standby router is 172.12.23.2 expires in 8.020

Virtual mac address is 0000.0c07.ac05

2 state changes
last state change 00:02:08

R3 is in Active state
while R2 is in Standby. The hosts are using the 172.12.123.10 address as their gateway
but R3 is actually handling the workload. R2 will take over if R3 becomes unavailable.

An IP address was assigned to the virtual router during the HSRP configuration process
but not a MAC address. However
there is a MAC address under the show standby output on R3
the active router. How did the HSRP process arrive at a MAC of 00-00-0c-07-ac-05?

Well
most of the work is already done before the configuration is even begun. The MAC address 00-00-0c-07-ac-xx is reserved for HSRP
and xx is the group number in hexadecimal. That's a good skill to have for the exam
so make sure you're comfortable with hex conversions. The group number is 5
which is expressed as 05 with a two-bit hex character. If the group number had been 17
we'd see 11 at the end of the MAC address - one unit of 16
one unit of 1.

The output of the show standby command also tells us that the HSRP speakers are sending Hellos every 3 seconds
with a 10-second holdtime. These values can be changed with the standby command
but HSRP speakers in the same group should have the same timers. You can even tie down the hello time to the millisecond
but it's doubtful you'll ever need to do that.

R3(config-if)#standby 5 timers ?

<1-254> Hello interval in seconds

msec Specify hello interval in milliseconds

R3(config-if)#standby 5 timers 4 ?

<5-255> Hold time in seconds

R3(config-if)#standby 5 timers 4 12

Another important HSRP skill is knowing how to change the Active router assignment. I'll show you how to do that
and how to configure HSRP interface tracking
in the next part of my CCNP / BCMSN exam tutorial!

Defined in RFC 2281
HSRP is a Cisco-proprietary protocol in which routers are put into an HSRP router group. Along with dynamic routing protocols and STP
HSRP is considered a high-availability network service
since all three have an almost immediate cutover to a secondary path when the primary path is unavailable.

One of the routers will be selected as the primary ("Active"
in HSRP terminology)
and that primary will handle the routing while the other routers are in standby
ready to handle the load if the primary router becomes unavailable. In this fashion
HSRP ensures a high network uptime
since it routes IP traffic without relying on a single router.

The hosts using HSRP as a gateway don't know the actual IP or MAC addresses of the routers in the group. They're communicating with a pseudorouter
a "virtual router" created by the HSRP configuration. This virtual router will have a virtual MAC and IP adddress as well.

The standby routers aren't just going to be sitting there
though! By configuring multiple HSRP groups on a single interface
HSRP load balancing can be achieved.

Before we get to the more advanced HSRP configuration
we better get a basic one started! We'll be using a two-router topology here
and keep in mind that one or both of these routers could be multilayer switches as well. For ease of reading
I'm going to refer to them only as routers.

R2 and R3 will both be configured to be in standby group 5. The virtual router will have an IP address of 172.12.23.10 /24. All hosts in VLAN 100 should use this address as their default gateway.

R2(config)#interface ethernet0

R2(config-if)#standby 5 ip 172.12.23.10

R3(config)#interface ethernet0

R3(config-if)#standby 5 ip 172.12.23.10

The show command for HSRP is show standby
and it's the first command you should run while configuring and troubleshooting HSRP. Let's run it on both routers and compare results.

R2#show standby

Ethernet0 - Group 5

Local state is Standby
priority 100

Hellotime 3 sec
holdtime 10 sec

Next hello sent in 0.776

Virtual IP address is 172.12.23.10 configured

Active router is 172.12.23.3
priority 100 expires in 9.568

Standby router is local

1 state changes
last state change 00:00:22

R3#show standby

Ethernet0 - Group 5

Local state is Active
priority 100

Hellotime 3 sec
holdtime 10 sec

Next hello sent in 2.592

Virtual IP address is 172.12.23.10 configured

Active router is local

Standby router is 172.12.23.2 expires in 8.020

Virtual mac address is 0000.0c07.ac05

2 state changes
last state change 00:02:08

We can see that R3 has been selected as the Active router ("local state is Active")
the virtual router's IP is 172.12.23.10
and R2 is the standby router.

There are some HSRP values that you'll need to change from time to time. What if we want R2 to be the Active router instead? Can we change the MAC address of the virtual router? I'll answer those questions in the next part of this HSRP tutorial!

Passing the BCMSN exam and getting one step closer to the CCNP certification means learning and noticing details that you were not presented with in your CCNA studies. (Yes
I know – you had more than enough details then
right?) One protocol you’ve got to learn more details about is VTP
which seemed simple enough in your CCNA studies! Part of learning the details is mastering the fundamentals
so in this tutorial we’ll review the basics of VTP.


In show vtp status readouts
the "VTP Operating Mode" is set to "Server" by default. The more familiar term for VTP Operating Mode is simply VTP Mode
and Server is the default. It's through the usage of VTP modes that we can place limits on which switches can delete and create VLANs.

In Server mode
a VTP switch can be used to create
modify
and delete VLANs. This means that a VTP deployment has to have at least one switch in Server mode
or VLAN creation will not be possible. Again
this is the default setting for Cisco switches.

Switches running in Client mode cannot be used to create
modify
or delete VLANs. Clients do listen for VTP advertisements and act accordingly when VTP advertisements notify the Client of VLAN changes.

VTP Transparent mode actually means that the switch isn't participating in the VTP domain as Servers and Clients do. (Bear with me here.) Transparent VTP switches don't synchronize their VTP databases with other VTP speakers. They don't even advertise their own VLAN information! Therefore
any VLANs created on a Transparent VTP switch will not be advertised to other VTP speakers in the domain
making them locally significant only. (I know you remember that phrase from your CCNA studies!)

Devices running VTP Transparent mode do have a little something to do with the other switches in the VTP domain
though. When a switch running in Transparent mode receives a VTP advertisement
that switch will forward that advertisement to other switches in that VTP domain.

Configuring switches as VTP Clients is a great way to “tie down” VLAN creation capabilities to switches that are under your physical control. However
this occasionally leads to a situation where only the VTP clients will have ports that belong to a given VLAN
but the VLAN still has to be created on the VTP server. (VLANs can be created and deleted in transparent mode
but those changes aren't advertised to other switches in the VTP domain.)


In the next BCMSN tutorial
we’ll take a look at the details of VTP.

To pass the CCNA exam and earn this important certification
you’ve got to know switching inside and out. While you’re learning all the basic switching theory
make sure to spend some time with the one of three switching modes Cisco routers can use.

Store-and-Forward is exactly what it sounds like. The entire frame will be stored before it is forwarded. This mode allows for the greatest amount of error checking
since a CRC (Cyclical Redundancy Check) is run against the frame before it is forwarded. If the frame contains an error
it is discarded. If there’s no problem with the frame
the frame is then forwarded to its proper destination.


While store-and-forward does perform error checking
the delay in processing the frame while this error check is run results in higher latency than the other modes you’re about to read about. The latency time can also vary
since not all frames are the same size.

Cut-through switching copies only the destination MAC address into its memory before beginning to forward the frame. Since the frame is being forwarded as soon as the destination MAC is read
there is less latency than store-and-forward. The drawback is that there is no error checking.

There is a middle ground
fragment-free switching. Only part of the frame is copied to memory before it is forwarded
but it’s the first 64 bytes of the frame
not just the destination MAC. (Why? Because if there is a problem with the frame
it’s most likely in the first 64 bytes.) There is a little more error checking than cut-through
but not as much latency as with store-and-forward.

Note that the latency of both cut-through and fragment-free is fixed; these modes always look at the first six or 64 bytes
respectively. Store-and-forward's latency depends on the size of the frame.
Learning the similarities and differences between these modes is an often-overlooked part of CCNA studies. Spend some time studying this important CCNA topic – you’ll be glad you did!

CCNA and CCNP candidates who have their own Cisco home labs often email me about an odd situation that occurs when they erase a switch's configuration. Their startup configuration is gone
as they expect
but the VLAN and VTP information is still there!

Sounds strange
doesn't it? Let's look at an example. On SW1
we run show vlan brief and see in this abbreviated output that there are three additional vlans in use:

SW1#show vlan br


10 VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

We want to totally erase the router's startup configuration
so we use the write erase command
confirm it
and reload without saving the running config:

SW1#write erase

Erasing the nvram filesystem will remove all configuration files! Continue?

[confirm]

[OK]

Erase of nvram: complete


00:06:00: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram

SW1#reload

System configuration has been modified. Save? [yes/no]: n

Proceed with reload? [confirm]

The router reloads
and after exiting setup mode
we run show vlan brief again. And even though the startup configuration was erased
the vlans are still there!

Switch#show vlan br


10 VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

The reason is that this vlan and VTP information is actually kept in the VLAN.DAT file in Flash memory
and the contents of Flash are kept on a reload. The file has to be deleted manually.

There's a little trick to deleting this file. The switch will prompt you twice to ask if you really want to get rid of this file. Don't type "y" or "yes"; just accept the defaults by hitting the return key. If you type "y"
the router attempts to delete a file named "y"
as shown here:

Switch#delete vlan.dat

Delete filename [vlan.dat]? y

Delete flash:y? [confirm]

%Error deleting flash:y (No such file or directory)



Switch#delete vlan.dat

Delete filename [vlan.dat]?

Delete flash:vlan.dat? [confirm]


Switch#

The best way to prepare for CCNA and CCNP exam success is by working on real Cisco equipment
and by performing lab tasks over and over. Repetition is the mother of skill
and by truly erasing your VLAN and VTP information by deleting the vlan.dat file from Flash
you'll be building your Cisco skills to the point where your CCNA and CCNP exam success is a certainty.

CCNA stands for Cisco Certified Network Associate - a certification for IT professionals that is issued by Cisco Systems
Inc.
one of the most successful computer networking companies. Cisco manufactures and markets a wide range of devices for both enterprises and telecommunications carriers. Cisco is an abbreviation of San FranCISCO.

The Cisco Certified Network Associate is an apprentice
or foundation level (along with Cisco Certified Design Associate)
within the three levels of certification that include Associate
Professional
and Expert. Basically
CCNA professionals are certified to install
configure
and operate LAN
WAN
and dial access services for small networks (100 nodes or fewer)
including but not exclusive to use of these protocols: IP
IGRP
Serial
Frame Relay
IP RIP
VLANs
RIP
Ethernet
and Access Lists. The certification is valid for three years
after which recertification may be sought.

In order to hold a CCNA certification
a candidate has to pass either the Cisco Certified Network Associate Exam or a combination of Introduction to Cisco Networking Technologies Exam and Interconnecting Cisco Networking Devices Exam. Main topics for these three exams include Planning and Designing; Design and Support; Implementation and Operation; Troubleshooting; and Technology. Other related topics may also appear on any specific delivery of the exam.

There are also some recommended training programs that may be taken before the above-mentioned examinations. These programs include Introduction to Cisco Networking Technologies (INTRO)
Interconnecting Cisco Network Devices (ICND)
and Additional Training (CCNA Prep Center Pilot). These trainings incorporate topics such as fundamental knowledge and comprehension of networking; how to select
connect
configure
and troubleshoot the various Cisco networking devices; sample questions
simulations
e-learning modules
labs
tips
etc.

You went to college and thought you were prepared for the job market. If you are going for entry-level work
yeah
you are prepared. However
to really get ahead
you need Microsoft certification
whether it is an MCP
MCSA
MCSE or any other string of letters. Quite a few people will go for multiple certifications to broaden their experience and scope of possible job opportunities.

Some of the Microsoft certifications require you have to have at least one year of practical experience in order to pursue a certification
namely an MCSE or Microsoft Certified Systems Engineer. It is important to have that experience that these certain certifications require because the training
like the MCSE training and the MCSE exams that follow
are very intense. In fact
some people will not only partake of the standard MCSE training
but also MCSE boot camps for more in-depth studies into their certification.

One standard benefit to having a Microsoft certification is that it is a great basic means of analyzing the aptitude of an employee. If you are a manager or owner in a business
you want some way to evaluate that employee’s skills. And if you are the employee
you know that your boss recognizes your abilities.

If you are on the hunt for a new job
then potential hiring managers and employers have a basis in which to assess your qualifications. Without that Microsoft certification on your resume
these employers would have no idea about your skills and most likely would consider someone else
someone with a certification
for the position you were aiming for.

If you do not have much hands-on experience in your field
but you do have the Microsoft certification to prove that you know the material
you would also have a leg up on anyone else applying for the same position that may have more hands-on experience
but no certification. For some reason
that certification
those little string of letters like MCP or MCSE
hold a lot of power.

Yet another benefit to holding a Microsoft certification or two is the money aspect of it all. Sure
you shelled out some major bucks to fund your education in those MCP courses or that MCSE training
but consider it an investment in yourself. With certification
you can bargain a higher salary and even reimbursement for your training!

Many professionals in the IT field or in a company in which you work in an IT department could benefit from Microsoft certification. Do you work as an Administrator for a network
mail or web server? Are you involved in the security of networks and the internet? Any of those positions and much more benefit with additional training and certification. Just think money! It is the biggest motivator. The more you know and can bring to a position
the more money you stand to make.

So think about going for your MCSE or MCP certification or any number of others available. More training; more knowledge; more money ... sounds like a no-brainer! Go nuts and get certified today!