[c-nsp] arp & vrf

[Sorin CONSTANTINESCU]

Hi,

I have a GSR running 120-28.S1, with 2 GigabitEthernet LC
crossconnected via an optical fiber patch. One of the interfaces is in
the default routing table (Gi4/0), and the other one is in a vrf.

#sh run int gi4/0
Building configuration...

Current configuration : 120 bytes
!
interface GigabitEthernet4/0
 ip address 10.0.0.1 255.255.255.252
 no ip directed-broadcast
 no negotiation auto
end

#sh run int gi7/0
Building configuration...

Current configuration : 146 bytes
!
interface GigabitEthernet7/0
 ip vrf forwarding test#4
 ip address 10.0.0.2 255.255.255.252
 no ip directed-broadcast
 no negotiation auto
end

I tried to ping 10.0.0.2 from the default routing table, but the
router couldn't learn an ARP entry because the router knew that
10.0.0.2 was on the same router.

#debug ip arp shows:

#show log | i 00b0.c285.4a00|0000.0000.0000
Nov 16 08:51:38: IP ARP: sent req src 10.0.0.1 00b0.c285.4a00,
                 dst 10.0.0.2 0000.0000.0000 GigabitEthernet4/0
Nov 16 08:51:38: IP ARP req filtered src 10.0.0.1 00b0.c285.4a00, dst
10.0.0.2 0000.0000.0000 it's our address
Nov 16 08:51:40: IP ARP: sent req src 10.0.0.1 00b0.c285.4a00,
                 dst 10.0.0.2 0000.0000.0000 GigabitEthernet4/0
Nov 16 08:51:42: IP ARP: sent req src 10.0.0.1 00b0.c285.4a00,
                 dst 10.0.0.2 0000.0000.0000 GigabitEthernet4/0
Nov 16 08:51:42: IP ARP req filtered src 10.0.0.1 00b0.c285.4a00, dst
10.0.0.2 0000.0000.0000 it's our address
Nov 16 08:51:44: IP ARP: sent req src 10.0.0.1 00b0.c285.4a00,
                 dst 10.0.0.2 0000.0000.0000 GigabitEthernet4/0
Nov 16 08:51:44: IP ARP req filtered src 10.0.0.1 00b0.c285.4a00, dst
10.0.0.2 0000.0000.0000 it's our address
Nov 16 08:51:46: IP ARP: sent req src 10.0.0.1 00b0.c285.4a00,
                 dst 10.0.0.2 0000.0000.0000 GigabitEthernet4/0
Nov 16 08:51:46: IP ARP req filtered src 10.0.0.1 00b0.c285.4a00, dst
10.0.0.2 0000.0000.0000 it's our address

The solution was to set static arp entries:

arp 10.0.0.2 00b0.c285.4b80 ARPA
arp vrf test#4 10.0.0.1 00b0.c285.4a00 ARPA

Is there another way to make traffic pass via the GBICs?

Regards,
-- 
Sorin CONSTANTINESCU
consta at gmail.com
Linux Registered User #222086