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Last Week CCNA Switching Lab

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Chigy

Technical User
Jul 29, 2007
9
GB

Team - have been loging to this site since I failed to recertify CCNA last week. A lot has changed!

I stumbled on the lab I got in the exam on one of the TestKing PDFs. I have some of the quetions, below, and I dont know what show commands to run on the swich to get the answers.

I had access to the console to one switch only:
LAB DESCRIPTION:
There are 4 switches in a partial mash. Sw-AC3 has the console. It is connected to VLan-R1 which has 4 vlan sub-if desfined Vlan-R1 connect to this SW only. To there is another Router through other switches then connected to ISP. Immediate neighbors are two switches, and this Vlan-R1.

1. What ports on Sw-AC3 are operating as trunks? (Select three.)

2. Which switch is the root bridge for VLAN 1?

3. From which switch did Sw-AC3 receive the VLAN information?

4. Out of which port on Sw-Ac3 would a frame containing an IP packet with a destination address that is not on a local LAN be forwarded?
 
1. show interfaces trunk
2. show spanning-tree (this will give mac address of root)
show mac-address-table (find mac address of root and this will give you the interface)
show cdp neighbor (this will give you the hostname connected to the interface above)
3. show vtp status
show cdp neighbor
4. show running-config (note the default gateway)
show cdp neighbor detail (this will provide ip to hostname)
show cdp neighbor (will give local interface assoc. with hostname)

Hope this helps.




Jim W MCSE CCNA
Network Manager
 
Thanks Jim.

On N.3, I still have problems. I remember I did a "show vpt status". What I need for #3 is the mac-address of the vtp server or the port on which it is connected before I run "show cdp neighbor...
 
Burt, if you do a show-mac-address-table, yeah you see the table, but I don't see how it can solve #3. Required is the ID of the VTP server.
 
It should match the IP address to the mac address---does this not show on the diagram?
Also, show cdp neighbor detail---the detail keyword is important. Are all the switches in the same VTP domain?

Burt
 
show vtp status

At the bottom of the output is an ip address that shows where the last change to the vlan database occurred (local updater). If it is 0.0.0.0 that means the change came from the local device which means it is the vtp server. If you see an ip address such as 192.168.1.1 that means the change was advertised through vtp and the mac address associated with the IP address is the server. show arp will give the ip address to mac address binding.

HTH
 
I had this switching question today on my CCNA but the 4th question was a little different. It gave the source and destination MAC address of a frame and asked what ports the frame would be sent out. You had to check 3 answers. The source MAC address appeared in the MAC table (from port fa0/6) but the destination MAC address did not. There were two switches and a router connected to this switch and also 4 host PCs. One of the host PCs was on fa0/6. Would the frame be sent to the other switches and the router? Seems that should be right but I'm not sure.

Also, does anyone know if you answer 4 out of 5 questions right on one of these type of simulator questions, do you get any credit? Or do you need to get them all right? Thanks!
 
GHARUS,

I too had the same issue with the same question and I too blew it. How can you find the destination MAC address.
I know for a fact I blew this entire question.

Last I knew and I could be wrong here is if you have 5 questions and you miss one of them the entire question is wrong. ie. question 49 has 5 parts and you miss one. Question 49 is listed as incorrect with no points awarded.

834 >.< so damn close.

Anyway, I too am looking for assistance with this part.

Jim, I cannot thank you enough with the "show commands". I had no idea they existed. Where these removed from the "sh ?" CLI on the sim. I sure do not remember seeing them there and I took the test 7 hours ago.....

Rick
 
hi guy's, having been through the CCNA hoop recently and was, shall we say, a little disappointed with my end resalt...
my question to anyone on the list is about finding CCNA exam-simulators with as close as possible scenarios as per the offical exam.
anything i've found/purchased in my travels has either been totally insufficient or barely comes close to the level of difficulty that's applied in the actual exam.

any help greatly appreciated

regards

Harry


 
Umm...try real routers and switches. If this is all you are doing, then you may become a "paper" cert. Don't want that now...

Burt
 
Real routers and real switches do make a big difference in preparing on the certs.

To help answer Gharus on the mac address question. If a switch does not know which port a mac address is on, it will forward it out all ports except for the one it was received on. I'm guessing you had 4 choices and one of which was the source port.

From what I've heard about scoring...not all questions are counted towards the final score, but I don't know if that is true or not. I don't think anyone really knows for certain how the scores are "graded".

 
lerdalt,

That is what I thought (it will forward out all ports except the source port). The problem is that there where 7 possible answers. One was the source port and one was a port that was not enabled (there was nothing connected to it as determined by a 'show interface' command). This left me with the 2 ports connected to the other two switches, a port connected to the router, and two ports that were connected to PC hosts (other than the source MAC). As far as I could tell there were 5 correct answers.
 
lerdalt,

You are so right - how Cisco exams are graded are a very tightly guarded secret :)

I was lucky enough to have a session with one of the heads of the CCNA exam design team at Cisco Networkers in San Diego several years ago. He confirmed that you might see from 0 to 5 "test" questions on any exam.

He also said that on any Cisco exam you need to pick the "best" answer from what is offered - you might have several that are "good" answers but only one is the "best" answer! Or in the case where you pick the 3 or 4 "best" answers - ALL might be "ok" but several will be "better" then the rest. He said this tends to seperate "those that understand it" from "those that just read a study guide"!

And we asked many detailed questions about scoring ..... ALL that he would not answer but always had a BIG smile :)

Just my thoughts!


E.A. Broda
CCNA, CCDA, CCAI, Network +
 
I agree with you Burt about using "real" routers and switches but they are rather expensive and not always readily available. The sims are good as well if you can get a hold of them.

Too many "paper" MCESs out there so I know where your coming from.

Gharus:
The MAC question you are talking about...
There was no option for "flood all ports" and you only had 2 or 3 choices out of 7 if I recall. That sound right?

Rick
 
Cheap on Ebay...that's what I did. 2500's can go for as little as $15/each.

Burt
 
Hey guy's , thanx for your kind responses. i initially decided to go with simulators as opposed to purchasing cisco hardware for my studies because the third party software i bought seemed to have the necessary constructive learning tools. the problem is that these network/exam simulators are dealing with setups of a basic nature ie/ host--switch--router--router--switch--host etc. along with the associated questions to suit.
my problem is that this is a level of difficulty far below what appeared in the actual ccna exam.
the purchasing of cisco hardware as a learning tool is fine and i understand the principle on "getting your hand's dirty" but as you can see up top in the question Chigy posted, how will the hardware help unless it comes with any practical scenarios with what to practice and gain an understanding so as to match the ccna exam level.

hope this makes sense

regards

Harry
"CCNA wannabe
 
I had an opportunity to look at the Boson netsim product awhile back. It was ok, close to the real thing, but there is a difference between the two. Not all the commands were available. Not that it was a big deal for the ccna level, but still made me really appreciate having the real thing around.

Maybe I was fortuneate enough to have some additional work experience to fall back on, but I kept making up my own labs. Not hard to setup 3 routers in series and setup routing using rip, ospf, and eigrp between them. Same with having a basic network with a couple of pc's and doing acl's to block web traffic.

As I've been working on building another home lab (used whatever equipment I had at work for CCNA and CCNP), here is what I've had in the back of my mind for the topology:
necessary equipment:
3 routers (mc3810s)
3 switches (2950 series)
2 pcs/laptops with web and ftp services loaded.

PC1 - Switches ( create a triangle for spanning-tree) - r1 - r2 - r3 - pc2

Granted, I'm looking at a little more advanced stuff just for QoS and more routing stuff, but depending on placement of the pc's, this could be a good starting point for ccna as well.

Biggest advice I have for any home labs, is fire off the debug commands. With spanning-tree and ospf especially it helped me to understand and see what happened during each of the steps before everything had converged.
 
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