Nexus 7k7 - How to SNMP context with four VRFs?

[Sven Hruza]

Dear all,

I have some Nexus 7700 devices and on each Nexus we have configured the default VRF with some VLAN interfaces and also four other VRFs with VLAN interfaces.

Per default I see only the interfaces of the default VRF in my SNMP management tool.

Also the ARP table can only be polled from the default VRF.

Now I want to poll also the interfaces in the other VRFs.

But with the snmp-server context configuration I found in some deployment guides I can only configure a context for one single VRF and not for all.

Is it possible to create a context containing all my VRFs to get all interfaces of the Nexus switch?

At first I try this with SNMPv2, but in future I want to use SNMPv3.

Thank you very much!

Sven

[marce1000]

 - Although not a direct answer, this may provide hints :

 https://supportforums.cisco.com/t5/network-management/how-to-snmp-to-get-nexus-7k-non-default-vrf-arp-table/m-p/2346419#M97657

M.

[Sven Hruza]

Thank you, but this configuration is only working with one single VRF and context.

If I try to configure more VRFs to the same context, it is overwritten.

And it is also not possible to map more than one context to the same community.

[Nathan Young]

I'm looking for the same answer.  I do not want to configure a unique SNMP string for each context.

[Sven Hruza]

I don't have an answer for SNMPv2.

But for SNMPv3 I think I figured out a solution together with my support partner.

Configure for each VRF a context:

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

snmp-server context <context-3-name> vrf <vrf-3-name>

With the CISCO-CONTEXT-MAPPING-MIB you can read the configured contexts.

The OID should be .1.3.6.1.4.1.9.9.468.1.1.1.2

These values you can use in another SNMPv3 walk with the option -N <context-1-name> to get things like IP interfaces, ARP table or something like that.

snmpwalk -v 3 -v3u <username> -a SHA -A <auth-password> -x <ENCRYPT> -X <encrypt-password> -N <context-1-name> <IP-address><OID>

For me it worked the best way to set the names of the contexts the same like the VRF names to make it a little bit transparent for the guys responsible for our inventory database.