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$ifDescr truncates at 61 characters?

Expert
Posts: 256
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I have an interface group for which the membership definition matches on a couple strings in the interface variable $ifDescr.  The Cisco OID for this is locIfDescr which is set by the interface "description" sub-command.  Cisco allows this string to be up to 255 characters.  From NetMRI interface displays, it appears that this is truncated to 61 characters.  Can anyone from Infoblox confirm if this is true and if it is intentional or an oversight?

The reason it matters is that our interface descriptions follow a template and the field/values we need to match on are beyond 61 characters.  Some interfaces that should become group members are not.  When I manually entered the description so that the strings were within the 61-character length, the membership succeeds.

Thanks.

Marty,

Adviser
Posts: 357
1644     0

Marty,

If ifAlias (http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en&translate=Translate&objectInput=1.3.6.1... is set, it takes precedence. It is only 64 characters. Could that be the issue?

John

ifAlias is populated

Expert
Posts: 256
1644     0

Thanks for that tip, John.

Yes, I see that ifAlias has the same values as locIfDescr but those are truncated at 64 characters as you surmised.

As I first reported, when I moved the string of interest so that it fit within the allowed size, the membership seemed to update correctly.  But since then, I found at least two more which did not.  The strings shown in Device Viewer -> Interfaces -> Configuration are stale, even after four days.  An SNMP walk shows the new values, and the Config Explorer diff shows when the change occurred.

So what triggers a refresh of the ifAlias values into the DB?  I looked through an SNMP debug output of ~18 hours and didn't find any obvious OID being collected for that.

It should do it every poll.

Adviser
Posts: 357
1644     0

It should do it every poll. You should probably open a support case.

Support case opened

Expert
Posts: 256
1644     0

Thanks for the confirmation on the intended behavior.  I already opened a support case.

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