SNMP ifInOctets|ifOutOctets on two routers.

[Sergey Alexeev]

Hi, all! I have 2 Cisco 2821 routers with the same configuration. IOS c2800nm-spservicesk9-mz.124-25b.bin.

When i try to get ifInOctets|ifOutOctets on subinterfaces via snmpwalk, an the one router is all OK, but other returns me zero.

For example:

IF-MIB::ifInOctets.100 = Counter32: 0 - there is the problem.

IF-MIB::ifInOctets.126 = Counter32: 440924398 - All OK.

When i try to get subinterface or interface description or ifInOctets on non-subinterface - all OK on both routers.

Sample subinterface configuration:

interface GigabitEthernet0/0.XYZ
description ---
encapsulation dot1Q 234
ip vrf forwarding 234
ip address 172.16.199.1 255.255.255.0
ip access-group interface_on in
ip access-group interface_on out
ip flow egress

Thanks for any help. If you need any output - please, ask me.

[Collin Clark]

The interface indexes are probably different (they can change after a reboot). You can view what interface has which index with the following command:

show snmp mib ifmib ifindex

Next change the query string to match the interface index.

IF-MIB::ifInOctets.100

You can set the indexes to be persistant with:

snmp-server ifindex persist

Hope it helps.

[Sergey Alexeev]

Thanks for hint, but subinterface is correctly up and in working state. We use persistent if index for countig clients traffic via netflow. Of course, interfaces & ifindexes are actually.

But because of the above mentioned problem, we cant monitor interface's traffic via Cacti on problematic router.

Sorry for my english, it really not so good.

[Sergey Alexeev]

Wow! I find answer. There need to configure

router(config)#vlan accounting input
router(config)#vlan accounting output

on router. Hope this can help you in situation, like this.