RE: MPLS tagging issue

What is the output of show mpls ldp neighbors? Is R3 sending the Lo to R4
as a route it is sending labels for?

Regards,
 
Tyson Scott - CCIE #13513 R&S, Security, and SP
Managing Partner / Sr. Instructor - IPexpert, Inc.
Mailto: tscott_at_ipexpert.com

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
Brian Buxton
Sent: Thursday, June 24, 2010 3:30 PM
To: CCIE Groupstudy
Subject: MPLS tagging issue

Hello all,

I am having trouble with a loopback not being tagged by a P router. R3 Lo0
can ping R5 Lo0, however the CE on vrf RED attached to R3 cannot ping the CE
on vrf RED attached to R5 even though the networks are making it to both PE
BGP tables. I think I have narrowed the issue to a P router (R4) that has
no CE attached. It does not appear to be tagging the R3 Lo0. This seems to
permit BGP to propogate, but break the actual traffic between the VRFs. I
am including "sh ip bgp vpnv4 vrf RED" on both R3 and R5 as well as "sh mpls
forwarding-table" on R2 and R4. Note the line in the R4 output that reads
"18 Untagged 3.3.3.3/3 ..." This is what leads me to believe the
problem lies on either R2 or R4. Any guidance is appreciated.
Thank you,
Brian

R3 - R2 - R4 - R5

R3 Lo0 = 3.3.3.3
R5 Lo0 = 5.5.5.5

R3#sh ip bgp vpnv4 vrf RED
BGP table version is 237, local router ID is 10.10.10.3
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 65080:70 (default for vrf RED)
*>i6.6.6.6/32 5.5.5.5 0 100 0 65060 i
*>i7.7.7.7/32 2.2.2.2 0 100 0 65070 i
*> 8.8.8.8/32 192.168.80.2 0 0 65080 i
*>i160.100.100.0/24 5.5.5.5 0 100 0 65060 i
*>i160.110.110.0/24 5.5.5.5 0 100 0 65060 i
*>i160.120.120.0/24 5.5.5.5 0 100 0 65060 i
*>i170.100.100.0/24 2.2.2.2 0 100 0 65070 i
*>i170.110.110.0/24 2.2.2.2 0 100 0 65070 i
*>i170.120.120.0/24 2.2.2.2 0 100 0 65070 i
*> 180.100.100.0/24 192.168.80.2 0 0 65080 i
*> 180.110.110.0/24 192.168.80.2 0 0 65080 i
*> 180.120.120.0/24 192.168.80.2 0 0 65080 i
*>i192.168.60.0 5.5.5.5 0 100 0 65060 i
*>i192.168.70.0 2.2.2.2 0 100 0 65070 i
r> 192.168.80.0 192.168.80.2 0 0 65080 i

R5#sh ip bgp vpnv4 vrf RED
BGP table version is 252, local router ID is 10.10.15.5
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 65080:70 (default for vrf RED)
*> 6.6.6.6/32 192.168.60.2 0 0 65060 i
*>i7.7.7.7/32 2.2.2.2 0 100 0 65070 i
*>i8.8.8.8/32 3.3.3.3 0 100 0 65080 i
*> 160.100.100.0/24 192.168.60.2 0 0 65060 i
*> 160.110.110.0/24 192.168.60.2 0 0 65060 i
*> 160.120.120.0/24 192.168.60.2 0 0 65060 i
*>i170.100.100.0/24 2.2.2.2 0 100 0 65070 i
*>i170.110.110.0/24 2.2.2.2 0 100 0 65070 i
*>i170.120.120.0/24 2.2.2.2 0 100 0 65070 i
*>i180.100.100.0/24 3.3.3.3 0 100 0 65080 i
*>i180.110.110.0/24 3.3.3.3 0 100 0 65080 i
*>i180.120.120.0/24 3.3.3.3 0 100 0 65080 i
r> 192.168.60.0 192.168.60.2 0 0 65060 i
*>i192.168.70.0 2.2.2.2 0 100 0 65070 i
*>i192.168.80.0 3.3.3.3 0 100 0 65080 i

R2#sh mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 10.10.15.0/24 0 Se0/0 10.10.10.4
17 Untagged 170.120.120.0/24[V] \
                                     0 Fa0/0 192.168.70.2
18 Untagged 170.110.110.0/24[V] \
                                     0 Fa0/0 192.168.70.2
19 Untagged 170.100.100.0/24[V] \
                                     684 Fa0/0 192.168.70.2
20 Untagged 7.7.7.7/32[V] 1254 Fa0/0 192.168.70.2
21 16 5.5.5.5/32 0 Se0/0 10.10.10.4
22 Pop tag 3.3.3.3/32 0 Se0/0 10.10.10.3
23 Pop tag 4.4.4.4/32 0 Se0/0 10.10.10.4

R4#sh mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 5.5.5.5/32 872 Se0/0.45 point2point
17 Pop tag 2.2.2.2/32 598 Se0/0.42 10.10.10.2
*18 Untagged 3.3.3.3/32 0 Se0/0.42 10.10.10.3*

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Received on Thu Jun 24 2010 - 15:34:33 ART