mpls error

[lkadlik]

Hi,

I recieved this error message in my logs at the same time a route was lost to another site

Dec 15 12:21:14.572: %TDP-5-INFO: VRF X: TDP ID removed

I was wondering if anyone could please shed some insight into what this might mean.

The route came back up within 10 minutes.

Thank you.

lynne

[Peter Paluch]

Hi Lynne,

This message usually indicates that the interface from which the LDP Router ID has been derived became inoperable, and as a result, the LDP RID had to change. Because you are obviously running the LDP in a particular VRF, you should have a look on the interfaces assigned to this VRF and verify whether they have not flapped. So this message was not an indication of the cause of your problem, rather it was a result of some another problem that is currently not possible to pinpoint without further information.

To preserve the stability of the LDP RID, I recommend configuring a loopback, assigning it to the VRF and forcing the LDP to use that loopback for RID. Note that in LDP, the RID is actually used as the IP address other LDP neighbors connect to, so the loopback must be also advertised in the routing protocol running in that VRF. For example:

ip vrf X
 rd 1:1
 route-target both 1:1
interface Loopback1000
 ip vrf forwarding X
 ip address 1.2.3.4 255.255.255.255
 ip ospf 2 area 0
mpls ldp router-id vrf X Loopback1000 force

Best regards,

Peter