IP Unnumbered problems

Been struggling to get IP unnumbered to work on a physical Gigiabit interface. I use the config below on a Port-channel subinterface all the time without an issue. Anyone see an issue with this config?

interface GigabitEthernet1/1.10
 encapsulation dot1Q 10
 ip vrf forwarding Traffic
 ip unnumbered Loopback1
 ip tcp adjust-mss 1400
 service-policy input DSCP
end

interface Loopback1
 ip vrf forwarding Traffic
 ip address 172.16.1.1 255.255.255.0
 ip tcp adjust-mss 1400
end

Find more posts tagged with

Comments

networker050184

What is the problem you are having?

vinbuck

Hosts on that particular network segment will only respond/pass traffic when the IP address is on the physical interface. Whenever I attempt to use the unnumbered config, there is no IP reachability to anything in that VLAN. I have the exact same config running on a gig interface in the same card type, chassis and IOS elsewhere and it works flawlessly.

I'm stumped

networker050184

Hmm ARP is the first thing that comes to mind here. I assume you have done a very thorough stare and compare with your other successful set ups, but if not that would be my first thing to look at. If you are 100% positive everything exactly the same looks like its TAC case time. Only other thing I can think of is this possibly being VRF related as I know a lot of stuff can have issues operating within a VRF of certain code trains.

vinbuck

ARP was my first thought also, ARP entries are incomplete when the ip unnumbered config is applied, but appear normal when the IP is applied to the interface. I'm almost positive that this is a bug, gonna talk to the TACies about it