NX-OS N9K uses SNMP to monitor routing sessions in multiple VRFs, caus

[a121402748]

Hi:

 I trying to monitor OSPF in multiple VRFs. I have created multiple context in SNMP. Here is what my config looks like:

snmp-server context default vrf default
snmp-server context abc01 vrf abc01
snmp-server context abc02 vrf abc02

snmp-server community abc01 group network-admin
snmp-server community abc02 group network-admin
snmp-server community default group network-admin

snmp-server mib community-map abc01 context abc01
snmp-server mib community-map abc02 context abc02
snmp-server mib community-map default context default

I have two questions now：

1.No matter how many vrfs there are, snmpwalk can only read data from one vrf, and the others have no data.

2.When the mib community mapping of a vrf is configured for the first time, only this vrf is valid. No matter how you modify or delete the configuration, only this vrf is still valid and cannot be changed. When you want to clear it, replace it with another vrf. , also has no effect

[balaji.bandi]

VRF means different instance, so you need to make configuration and poll per VRF based.

what nexus code running here,. worth check the configuration guide :

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/105x/config-guides/cisco-nexus-9000-series-nx-os-system-management-configuration-guide-release-105x/m-configuring-snmp-10x.html?bookSearch=true

[a121402748]

I know this. I am following the official configuration now, but problems still occur.

[balaji.bandi]

If you following the document that should work, can you tell us what code running, post snmpwalk ? is this v2 or v3

[Deepak Kumar]

Hello, 

Are you using SNMv2 or SNMPv3? I have seen that it works with SNMPv3 with the following type of configuration:

Configure for each VRF context:

snmp-server context <context-1> vrf <vrf-1>
snmp-server context <context-2> vrf <vrf-2>

Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 10.5(x) - Configuring SNMP [Cisco Nexus 9000 Series Switches] - Cisco

Search for "Multiple Instance Support"

[a121402748]

In theory both v2 and v3 can work. I am currently using v2 or v3 and it has no effect, but when I use other routers or other types of switches (such as 3850), it is effective.

[a121402748]

There should be no problem with the configuration. I think it’s a problem with the switch itself. Maybe the software version is inappropriate.