Switch stack reverted to old IP.

[stu1892]

Evening!

 

A couple of switch stacks of ours have reverted back to an old ip that is no longer in our scope, although it's the same subnet mask, which is why I guess they're communicating with stacks on the new scope?

 

Could this be causing a massive problem we have with our network almost grinding to a halt for 5-10 minutes while classes are logging on, like a bottle neck effect?

One of them has all the servers patched...

 

Found out late yesterday about the switch and obviously not in until Monday.

 

Hoping if I change the ip back it will sort itself out.

[glennda]

what make are they? and any chance they could have been power cycled.

 

Had a 3com backbone that lost all its settings when the power went off as when configured via telnet there is an extra command to make it perm remember the settings

[stu1892]

They're cisco. One of which may have been installed after the ip scope changed so I don't know what that could have reverted to.

 

Yeah powere cycling did pop into my head when I seen the setting had reversed. Could have been cycled. There was a power surge two weeks ago and that may have been the start of the problems. I know the phone system was totally screwed by it.

[FN-GM]

With cisco switches you need to set the running config to the startup config. This will stop it loosing the settings

[SYNACK]

Probably the config settings, make sure that you copy the running configuration to the start config.

 

make sure it is in elevated mode with the "enable" command then issue the "copy run start" command when you have all the right settings configured.

Hit enter to accept the default location, do not change the save location unless you know what you are doing as you can wipe the flash accidentally.

[stu1892]

Can I do this through the console?

 

Not done a lot of switch work.

 

Could this be causing our performance issues??

[SYNACK]

Yes you can issue these commands via the console or telnet, if there are some settings that have been changed then this could very well have caused some of the slow down. Without knowing the original setup it is impossible to know what has changed and is causing the slowdown without having the config files and knowing a lot more about the network.

 

Your best bet may be to contact whoever set them up initially to redo the settings then make sure that the configs are saved and backed up.

[stu1892]

I'm pretty sure they're unmanaged. One if the switches in the stack are labelled for teaming I believe, but no extra set up.

 

In fact when I changed the IP address in the summer, that's all that was changed. Perhaps the original running setup was copied to the startup setup, meaning it's only the IP that will need changing again.

 

Would this happen at any power cut / restart. Or have we been unlucky.

 

Just wondering as we have had plenty of powercuts since the IP and this is the first case of bad network performance.

[stu1892]

Going to have a look at this this morning.

 

First, I'm actually going to have to learn how to console into the switches! Always been lazy in using Cisco Network Assistant!

[stu1892]

Managed to set up a spare workstation on the old subnet, so i can now connect to the switches that have reverted back. through Network Asistant.

 

My plan is now, to back up the configs as they are. (causing issues or not)

Change problematic IP.

Copy Running Config to Startup config.

Backup settings.

 

All can be done though CNA, right?

[SYNACK]

Should be able to do it through CNA, I have not used it in a very long time though so can't be absolutely sure, they may have changed it.

[stu1892]

Yeah, you can. I'm amazed, i've found a Help menu that actually helped!

[stu1892]

So the running configuration should change instantly, and the startup, only after a restart?

[SYNACK]

The running config is the one loaded into memory and actually in use, the startup config is the configuration stored to nonvolitile ram which is loaded into the running config and used when the switch is restarted.

 

The startup config should show up with your changes immediatly after you have saved the running config to it.

[stu1892]

But it should start operating on the new IP instantly as soon as i apply the change through CNA?

 

Sorry for the number of (probably repetitive) questions...But...

 

Do you save the configuration to All devices or just the stack i'm on? Or does all devices mean all the switches in the stack?

 

By the way this is all for the 'Commanding Switch IP' apparently, if that makes a difference.

Edited March 8, 2010 by stu1892

[SYNACK]

Yes that is correct

[stu1892]

Right, they're all done.

 

I've saved the config, but haven't restarted the switches yet, and i'm in no rush to do so either to be honest.

 

All three switches had no DNS settings or if they did, they were wrong, so that can't be helping at all!

 

I'll only know by this time tomorrow if it was the cause to our huge performance issues.

 

Whether it was or not, it still needed to be done.

 

Thanks for everyone's help, much appreciated.

 

Stu

[waldronm2000]

If you're unsure, I would suggest restarting the switches just to ensure you've saved the config properly. Preferrably do it in the evening when there are fewer users. It's just that if you haven't properly saved the config it would be better to know that now than in a few weeks or months, when they next power down.

[stu1892]

Yeah, that's the reason i wanted to get them out of the way. My boss also asked me to try and prevent a restart. However, i can't get access to the building for the main stack at this time, thanks to poxy politics from people who haven't got a clue.

 

Can i reboot them from within CNA?

[waldronm2000]

Sorry, don't know (I don't use CNA), but if you telnet in, you can use the reload command.