[c-nsp] arp & vrf

[Rodney Dunn]

If you change the mac-address for one of the
interfaces does it work then?

>From an IP standpoint the router shouldn't 
do any comparison between a vrf and non-vrf
interface for ip address conflict.

Rodney

On Tue, Nov 16, 2004 at 09:10:29AM +0200, Sorin CONSTANTINESCU wrote:
> 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
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