ambiguous snmp community string on 1900

Answered Question
Aug 9th, 2007

We are trying to change the snmp community string on a Catalyst 1912. The old string was a mix of letters and numbers and the new string will be as well (and the same length). However when we try and change it we get an error message saying ambiguous string. The switch will only accept a string of all letters. We can't even re-apply the last string that's been working for a couple of years. Anyone any ideas? I can't find any other reports of this on the website. Firmware version is V9.00.06

Thanks in advance,

Zac

I have this problem too.
0 votes
Correct Answer by Joe Clarke about 9 years 4 months ago

The reason this happens is because of a bug fix that went into 9.00.05. The problem was that the 1900/2820 switches do not do community string indexing like other Cisco switches. They acknowledged a string that ends in number to be string+vlan where vlan is the number component.

The bug, CSCdv35159, was fixed such that strings that end in any combination of numbers and '@' will be disallowed. You will need to pick a string that ends with letters. The string should not contain a '@' and numbers are valid only within the string (not at the end).

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Pavel Bykov Thu, 08/09/2007 - 04:12

Eh... That's one ancient piece of HW you got there.

Try two things:

1. Try setting up your SNMP string using a menu

2. Try setting up your SNMP string using command line. Go to "command line" (letter K), and display configuration using "show conf". Find how the string should be configured, and try configuring it using "command line" commands. E.G. "config t" "snmp-server community" or whatever is the command on that piece of hardware.

zac.quinn Thu, 08/09/2007 - 04:17

Unfortunantely we've already tried both methods. We can set the string to pretty much anything we like as long as its all letters.

Pavel Bykov Thu, 08/09/2007 - 04:53

I'm sure it's the problem with proceedure that check the string.

How long is your string? Try making it longer. And don't use numbers at beginning or the end.

Also (i'm not sure if that is possible in 1900) try changing configuration, and then loading it directly into startup configuration. Into some file in nvram... I'm not sure how that would be done.

zac.quinn Thu, 08/09/2007 - 06:08

Thanks for your help. As the new strings are exactly the same format in terms of character type and length as the old ones, and that as we can't reinstate the old ones, I'm coming to the conclusion that it's an issue with the firmware version. So I'm going to downgrade back to v9.00.04, as I think the strings were installed at that point in the devices history, hopefully change the strings and then upgrade back up to v9.00.06.

It does appear to be the number at the end of the string that's causing the problem. I don't really want to have to remember that the half dozen or so of these boxes are setup differently to the rest of the fleet unless I really have to!

Regards,

Zac

Correct Answer
Joe Clarke Thu, 08/09/2007 - 10:39

The reason this happens is because of a bug fix that went into 9.00.05. The problem was that the 1900/2820 switches do not do community string indexing like other Cisco switches. They acknowledged a string that ends in number to be string+vlan where vlan is the number component.

The bug, CSCdv35159, was fixed such that strings that end in any combination of numbers and '@' will be disallowed. You will need to pick a string that ends with letters. The string should not contain a '@' and numbers are valid only within the string (not at the end).

Actions

This Discussion