How to bring up an interface

[Rinnt]

Hi,

I'm below novice when it comes to Cisco. However, when I noticed a port on our 2900 switch was orange, I decided to investigate. I telneted in, and typed "show interface" (bascially the only command I know) and noticed that port 6 is down! My questions are these:

How do I bring the interface backup?

What would cause it to go down?

Thanks for the help

 

[Guest_imported]

do this under telnet

1.) config t
2.) int <INTERFACE_NAME & PORT NUMBER>
3.) no shutdown
4.) press Ctrl-Z
5.) wri mem

that's it.. if you have any question you could just easily put a '?' question mark on the prompt to see the available commands.

Switch#? <--- that should give you all the help you need.

 

[tiremd]

If that doesn't do it, you could have a speed or duplex mismatch on that port which could cause it to be down. You can try setting them to whatever they need to be (full or half, 10 or 100), instead of letting it autonegotiate......that might help.

 

[Rinnt]

OK well I tried sc00ps idea. Unfortunately it did not work. tiremd sounds like he might know something . Could you please reduce your language to newbie talk? I have not a clue how to disengage the autonegotiate... Thanks!

 

[tiremd]

You'll also want to make sure the cable that is attached to that port is hooked to something that is good and functional.

To set the speed and duplex, you'll do something like the following:

Switch#>conf t
Switch#(configure)>interface fa0/1 (or whatever your interface number is)
Switch#(configure-int)>speed 10 (or speed 100)
Switch#(configure-int)>full-duplex (or duplex full, not sure of the exact syntax, you can use ? at any point for more info...or substitue half instead of full)
Switch#(configure-int)>end
Switch#>

Hope that helps...if that doesn't do it, try moving the cable to another port if you have one available, see if that port is ok...if not, check the device on the other end..

Good luck...

 

[Rinnt]

I have to wait for my tone generator to arrive in order to find a live connection to plug in. In the mean time, I have not even a cable plugged into this port but it still remains lit with an orange lit. What gives?

 

[tiremd]

that's a different story if a port is amber without anything attached... port should be down and led unlit with nothing attached. What port is it? Ports 1-8 are used to indicate POST test diagnostics during bootup. If one stays amber it could indicate a problem... hopefully this isn't your problem. is the switch in production? If not, maybe you can console to it directly and reboot and watch the diagnostics for any failures...

POST Test Descriptions:

LED 1
DRAM

LED 2
Flash memory

LED 3
Switch CPU

LED 4
System board

LED 5
CPU interface ASIC

LED 6
Switch core ASIC

LED 7
Ethernet controller ASIC

LED 8
Ethernet interfaces

 

[Rinnt]

Ouch, unfortunately it is in production... and it is Port 6 that is illuminated. Last night after hours I pulled the plug on it to reboot it... when it was coming up, I think there may have been more then port 6 that was amber. Anyway, 6 is the only one amber now but that still isn't right. Btw what is ASIC?

 

[tiremd]

I'm not sure what ASIC is.. you'd have to maybe check the Cisco website.

I think during bootup, 1-8 will all be amber and then the amber lights will go out as they pass diagnostics.. It would be helpful if maybe overnight you could reboot while looking at the console output. Aside from 6 being amber, you should see some failure reports during boot if that is your problem... hopefully not and its something else simple..

 

[Rinnt]

Ok thanks... I will probably try sometime early next week. Can you give me the step by step procedure for shuting down the switch thru the console? And will the output automatically be displayed on the screen?

Thanks again

 

[tiremd]

If you can reboot, its worth a try... if you are directly consoled in and and able to issue commands, you'll want to issue a 'reset' or 'reload', can't remember which works on that switch... you'll want to make sure the config is saved first ('sho conf' - will show you what the startup config will be) ('write mem' or 'copy run start' will save the config)...in fact it may even ask if you want to save when you reload it. Once you reload, it will dump the diagnostic info to the screen during the reboot...

 

[Degg]

ASIC is 'Application Specific Integrated Circuit', or something like that. Basically, an Electrical Engineer comes up with some huge circuit that uses a bunch of different IC's (chips) to do a certain function. then they go to a company that makes ASIC's and they put the whole circuit into one chip. this elimiates using tens or hundreds of individual IC chips to do the job. you have a single point of failure, it takes up less space, etc.

degg

 

[Rinnt]

tiremd,

I tried what you suggested but unfortunately it didn't work. I was able to &quot;sh conf&quot; then &quot;write mem&quot;. But as soon as I did &quot;reload&quot;, it disconnected me... no diagnostic info was dumped to the screen. Any ideas??

 

[Rinnt]

Also, I have a new issue! Port 5 is now flashing green/amber... and I noticed that it has an excess of 442,000 output errors! What could this one be now?

 

[tiremd]

It doesnt' sound healthy....not sure what the problem is now.... sounds like a hardware failure, but just in case its not, maybe you could cut/paste your config to a post so that we can look it over.... you can delete any passwords or ip's if you want...

 

[micon55]

I have seen this problem first hand, and it appears that you have a looping problem on your switch.
You will have to check your physical connections to make sure that there are no loops between the switch ports.

In simple terms, is there a connection from one of your 'working' ports to perhaps a hub and then back into another port? It might not be noticable if you have hubs daisy chained together.

You could also run the 'show spantree' command on your switch.

The next step would be to remove some of the other switch port connections, (out of hours), and see if your light changes to green.

I would be 90% confident that the port is unable to 'come up' because a spanning tree function on the switch will not allow it.
Good luck

M

 

[kkt]

Sounds like you have a port that has gone bad in your switch. Typically when ports go bad on catalysts you lose all 4 or 8 ports that the controller controls. Sometimes you do lose just one port. If you console into the switch you should check out the POST. It will probably tell you your port has failed a loop-back test. The port would only be amber if you had a potential spanning tree loop and it was placed in blocking mode, but since you unplugged the cable and the light was still lit, you then know the port is bad for sure. Since you have a 2924 that switch is covered by a limited lifetime warranty. This is about 9 years or so. You should be able to call TAC, tell them your port has failed loop-back and gone bad and you should be able to get a new switch with their 10 day Advanced Replacement plan, for Free. On your other port that has a ton of errors, it sounds like you have a duplex/speed problem. Some NICs don't play the autonegotiation game well and may need to be locked down on Speed and Duplex.

Hope that helps,

Kurt

 

[Rinnt]

Wow, thanks for the info. I was not aware of the warrenty. But just to make certain, how do I check the POST? I tried telneting in to reboot and observe it but had no luck... It disconnected me. And by the time I was able to get back in the 2900XL was already back up.

RE: the other error with green/amber flashing. Could that just be collisions? I noticed that it's only during backups.

Finally, If I do replace the unit, how hard would it be for a complete newbie to configure the new 2900XL? I would be totally lost, but am assuming I need to copy some sort of config file?

Thanks again

 

[MJewell]

you could telnet into the switch and download the entire config file to a text file, then just reupload it in text format on the new switch....

-Mike

 

[wybnormal]

Dont even need to download the config.. just cut and paste it to the new switch. Use a terminal program like Teraterm that allows you to change the number of lines to keep in memory.. do a show running-config.. highlight and copy it.. paste it into notepad and save it.

Go to the new switch, login, go into enable mode.. bring up notepad, load the saved config, highlight it all, paste it into the new switch.. then save running-config on the switch. this takes less then 10 seconds to config the new switch.

MikeS
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