CSC Using LDP and IGP

From: Marko Milivojevic (markom@vodafone.is)
Date: Mon Jul 02 2007 - 12:04:33 ART


It is entirely possible that this is Dynamips/Dynagen related issue. I
also posted on Hacki's forum, but I would just like to confirm that I'm
not misconfiguring something, before blaming the software for my errors
;-)

I am using 12.2(25)S11 SP IOS images. When configuring CsC between two
emulated 7200 routers, LDP keeps flapping and I cannot ping connected
interfaces. In the example below, R2 (CSC-CE) is connected to R3
(CSC-PE) using Se1/1. I could post IGP configs, but I somehow doubt they
are relevant (OSPF running on all interfaces in main routing table on
CSC Customer and in VRF on CSC-PE).

R2:
interface Serial1/1
 ip address 172.16.23.2 255.255.255.0
 ! not quite sure if this needed, but it doesn't change behaviour when
removed
 mpls ldp discovery transport-address interface
 mpls label protocol ldp
 mpls ip
 serial restart-delay 0
 no clns route-cache
!

R3:
interface Serial1/1
 ip vrf forwarding AS2
 ip address 172.16.23.3 255.255.255.0
 ! not quite sure if this needed, but it doesn't change behaviour when
removed
 mpls ldp discovery transport-address interface
 mpls label protocol ldp
 mpls ip
 serial restart-delay 0
 no clns route-cache
!

Now, the fun part:

Code:
R2#ping 172.16.23.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.23.3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#int se1/1
R2(config-if)#no mpls ip
R2(config-if)#end
R2#
00:52:49: %LDP-5-NBRCHG: LDP Neighbor 172.16.23.3:0 is DOWN
00:52:50: %SYS-5-CONFIG_I: Configured from console by console
R2#ping 172.16.23.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.23.3, timeout is 2 seconds:
..!!!
Success rate is 60 percent (3/5), round-trip min/avg/max = 4/9/16 ms

I am semi-suspecting that this is Dynamips-related issue (it could be
IOS, but I'm experiencing similar problem when using 3640 Telco image).
Did someone else experience something like this?

Of course, it's always possible that I horribly misconfigured something,
but I was always able to ping connected interface even if that was the
case.

Any ideas?



This archive was generated by hypermail 2.1.4 : Sat Aug 18 2007 - 08:17:39 ART