I think Cisco is truncating the interface descriptions when being
pulled via SNMP using the standard oid IF-MIB::ifAlias at 64
characters. Juniper doesn't do the same thing so I don't think it's a
requirement of that OID.

Example interface config.
interface GigabitEthernet0/2
description This is a test interface descriptoin that is very long.
There seems to be a problem with ifalias on Cisco devices truncating
the output....

SNMP get using ifAlias
IF-MIB::ifAlias.3 = STRING: This is a test interface descriptoin that
is very long. There s

SNMP get using the depreciated 1.3.6.1.4.1.9.2.2.1.1.28 from OLD-CISCO-
INTERFACES-MIB
SNMPv2-SMI::enterprises.9.2.2.1.1.28.3 = STRING: "This is a test
interface descriptoin that is very long. There seems to be a problem
with ifalias on Cisco devices truncating the output...."

Just wondering if there was a better way to do this via SNMP than to
use a depreciated MIB file.

Paul

Cisco is right, see SYNTAC of ifAlias in IF-MIB

ifAlias OBJECT-TYPE
SYNTAX DisplayString (SIZE(0..64))
MAX-ACCESS read-write
STATUS current
DESCRIPTION
....
::= { ifXEntry 18 }

As I remember you have to be lucky to get 64 bytes at all. Several other
vendors implemented SYNTAX SnmpAdminString wich is 32 characters long.

Paul Thomas schrieb: