problems retrieving duplicate IP addresses through SNMP on Cisco Routers

Question

I have a few interfaces on my Cisco 2801 router, the interfaces are configured in different VRFs and all have the same IP address:

interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface Loopback1
 ip vrf forwarding RED
 ip address 2.2.2.2 255.255.255.255
!
interface Loopback2
 ip vrf forwarding BLUE
 ip address 1.1.1.1 255.255.255.255

When i use snmpbulkget on my linux machine to try and get the interface information, I only get the IP of one of the interfaces. This happens with loopbacks as well as physical interfaces. Any ideas on how I can get the rest of the interfaces in this case? Here is the the output from the snmpbulkget:

snmpbulkget -v 2c -c cisco123 10.100.70.159 .1.3.6.1.2.1.4.20.1
IP-MIB::ipAdEntAddr.1.1.1.1 = IpAddress: 1.1.1.1
IP-MIB::ipAdEntAddr.2.2.2.2 = IpAddress: 2.2.2.2
IP-MIB::ipAdEntAddr.10.100.5.159 = IpAddress: 10.100.5.159
IP-MIB::ipAdEntAddr.10.111.5.45 = IpAddress: 10.111.5.45
IP-MIB::ipAdEntAddr.50.50.50.50 = IpAddress: 50.50.50.50
IP-MIB::ipAdEntIfIndex.1.1.1.1 = INTEGER: 8
IP-MIB::ipAdEntIfIndex.2.2.2.2 = INTEGER: 7
IP-MIB::ipAdEntIfIndex.10.100.5.159 = INTEGER: 1
IP-MIB::ipAdEntIfIndex.10.111.5.45 = INTEGER: 5
IP-MIB::ipAdEntIfIndex.50.50.50.50 = INTEGER: 10

Notice that the 1.1.1.1 address only returns once. All advice is appreciated, thanks!

Answer 1

Essentially, you need to associate an SNMP context with a particular VRF.

The Cisco configuration guide - http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/12-4t/snmp-12-4t-book/nm-snmp-vpn-context.html

An example:

Router(config)# snmp-server context context1 // create a context named context1
Router(config)# ip vrf BLUE // enters VRF configuration mode
Router(config-vrf)#context context1 //Associates an SNMP context with a particular VRF
Router(config-vrf)# end

Note: In Cisco IOS Release 15.0(1)M and later releases, the context command is replaced by the snmp context command. See the Network Management Command Reference for more information.

Router(config)# snmp-server user customer1 group1 v3 // Configures a new user to an SNMP group
Router(config)# snmp-server group group1 v3 context context1 // associate a group with a context

Note: Users and groups only exist in SNMPv3 and groups should exist prior to adding users to them.