02-09-2009 01:05 AM - edited 03-04-2019 03:28 AM
Hello everyone,
my company had a power outage over the weekend that apparently lasted longer than the UPS' could handle, and several of our switches lost power. No big deal, I back up the running configs every night at midnight, but now I'm unable to SSH/Telnet in to two of my switches (they're physically on top of each other). They seem to be functioning fine otherwise, and I can access them via HTTP, they react to pings and the attached clients haven't called to complain about network access, but I can't figure out why SSH support is suddenly gone.
Anyone have any ideas? Would rebooting the switches help?
02-09-2009 03:04 AM
Someone has likely forgot to save configuration. You need to connect locally, reconfigure, save.
In critical applications it's also important to do a power failure test to see if everything come back up as expected.
02-09-2009 03:07 AM
That's just the thing... I remember saving the configs on Friday, which I can confirm by the fact that what I changed still works today, with the power failure in between. The only thing that's not how it should be is the SSH access...
02-09-2009 03:10 AM
Invariably once on site you will identify some detail.. It's not a known problem so you will need to do your investigations.
02-09-2009 01:49 PM
Can you "cluster" into the two switches?
Presume the following:
Working switch = SwitchA
Notworking switch = SwitchB
Here's how it works (hoping you got the right IOS):
SwitchA#sh cdp neighbor
! To see if you can see SwitchB.
SwitchA#config t
SwitchA(config)#cluster enable SwitchA
! This line enables clustering on the working switch.
SwitchA#end
SwitchA#sh cluster candidate
! Look for SwitchB's MAC address.
SwitchA#config t
SwitchA(config)#cluster member mac
! Takes about 3 seconds if all goes well. You'll get "password incorrect" if the password is wrong. If you get "Access Denied" or something ... can't be helped anymore.
SwitchA(config)#end
SwitchA#rc 1
! Remote Cluster to the "first" switch (aka SwitchB)
Hope this works.
02-09-2009 11:48 PM
I figured out what the problem was. Apparently the power outage and subsequent reboot caused the switches to chanve the access-class for the VTY lines, meaning they were set for an access-list that didn't exist.
I swear I don't know how that happened. I was on both switches two day before via SSH because I needed to configure ports for new clients there, and I saved the configs. Strange.
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