Inter-AS MP-BGP

From: Rodrigo Paes (rpaes@pobox.com)
Date: Sat Mar 26 2005 - 20:28:52 GMT-3


Hi all

I'm burning my head here and I can't figure out what's happening

R6, R7 and R4 are in AS 2048, and BB2 and BB3 are in AS 1025, they are
running inter-AS MP-BGP... below you can see the configs.... but here is
the problem, or maybe it's not a problem, just a situation ;-)

R6 ----- R7 ----- R4
 | |
 | |
BB2 --- BB3

when I do a "sh tag forwarding-table" in R6, he shows me all the routes
that BB2 is sending him

Rack1R6#
Rack1R6#
Rack1R6#sh tag for
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Untagged 142.30.67.7/32 0 Vi3 point2point
17 0/33 150.50.7.0/24 0 AT0/0/0.200
point2point
18 0/34 142.30.74.0/24 0 AT0/0/0.200
point2point
19 0/35 150.50.4.0/24 0 AT0/0/0.200
point2point
20 Pop tag 51.0.6.1/32 0 Se1/0.991 point2point
29 23 1025:20:28.20.4.0/24 \
                                     0 Se1/0.992 point2point
30 24 1025:20:28.20.5.0/24 \
                                     0 Se1/0.992 point2point
34 40 1025:21:28.20.4.0/24 \
                                     0 Se1/0.992 point2point
35 41 1025:21:28.20.5.0/24 \
                                     0 Se1/0.992 point2point
36 25 1025:30:28.30.1.0/24 \
                                     0 Se1/0.992 point2point
37 26 1025:30:28.30.2.0/24 \
                                     0 Se1/0.992 point2point
38 27 1025:30:28.30.3.0/24 \
                                     0 Se1/0.992 point2point
39 42 1025:31:28.30.4.0/24 \
.
.
.
.

if I do the same thing on R7... nothing....

Rack1R7#
Rack1R7#
Rack1R7#sh tag for
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Untagged 142.30.67.6/32 0 Vi6 point2point
17 Untagged 142.30.74.4/32 0 Mu47 point2point
18 0/34 150.50.6.0/24 0 AT0/0.200 point2point
19 Pop tag 150.50.4.0/24 0 Mu47 point2point
20 Untagged 53.0.7.1/32 0 Se1/0.993 point2point
Rack1R7#

Now comes the really weird part..... R4 prefers the routes coming
through R7, isn't that nice... ;-)

Rack1R4#
Rack1R4#sh ip bgp v v rednet
BGP table version is 41, local router ID is 150.50.4.4
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: 2048:41 (default for vrf rednet)
*>i28.10.1.0/24 150.50.7.7 200 100 0 1025 1021 ?
*>i28.10.2.0/24 150.50.7.7 200 100 0 1025 1021 ?
*>i28.10.3.0/24 150.50.7.7 200 100 0 1025 1021 ?
*>i28.10.4.0/24 150.50.7.7 1200 100 0 1025 65000
1021 1021 ?
*>i28.10.5.0/24 150.50.7.7 1200 100 0 1025 65000
1021 1021 ?
Rack1R4#

I'm running IS-IS as the IGP, but I don't think this has anything to do
with it

Any of you guys have any reason for that ?????, or even better ... a
solution :-)

here are the configs, at least the interesting parts...

R6 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Rack1R6#sh run | b bgp
router bgp 2048
 no synchronization
 bgp router-id 150.50.6.6
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 51.0.6.1 remote-as 1024
 neighbor 52.0.6.1 remote-as 1025
 neighbor 150.50.7.7 remote-as 2048
 neighbor 150.50.7.7 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
 neighbor 51.0.6.1 activate
 neighbor 51.0.6.1 send-community both
 neighbor 52.0.6.1 activate
 neighbor 52.0.6.1 send-community both
 neighbor 150.50.7.7 activate
 neighbor 150.50.7.7 next-hop-self
 neighbor 150.50.7.7 send-community both
 no auto-summary
 exit-address-family
!

R7 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Rack1R7#sh run | b bgp
router bgp 2048
 no synchronization
 bgp router-id 150.50.7.7
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor PEs peer-group
 neighbor PEs remote-as 2048
 neighbor PEs update-source Loopback0
 neighbor 53.0.7.1 remote-as 1025
 neighbor 150.50.4.4 peer-group PEs
 neighbor 150.50.6.6 peer-group PEs
 no auto-summary
 !
 address-family vpnv4
 neighbor PEs activate
 neighbor PEs route-reflector-client
 neighbor PEs next-hop-self
 neighbor PEs send-community both
 neighbor 53.0.7.1 activate
 neighbor 53.0.7.1 send-community both
 neighbor 150.50.4.4 peer-group PEs
 neighbor 150.50.6.6 peer-group PEs
 no auto-summary
 exit-address-family
!

R4 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Rack1R4#sh run | b rednet
ip vrf rednet
 rd 2048:41
 route-target export 1025:1010
 route-target import 1025:2010
!
Rack1R4#sh run | b bgp
router bgp 2048
 no synchronization
 bgp router-id 150.50.4.4
 bgp log-neighbor-changes
 neighbor 150.50.7.7 remote-as 2048
 neighbor 150.50.7.7 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
 neighbor 150.50.7.7 activate
 neighbor 150.50.7.7 send-community both
 no auto-summary
 exit-address-family
 !
 address-family ipv4 vrf rednet
 no auto-summary
 no synchronization
 exit-address-family
!

BB2 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Rack1BB2#sh run | b bgp
router bgp 1025
 no synchronization
 bgp router-id 52.1.1.1
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor PEERs peer-group
 neighbor PEERs remote-as 2048
 neighbor PEERs route-map EXPORT_MAP out
 neighbor 52.0.2.2 peer-group PEERs
 neighbor 52.0.3.2 peer-group PEERs
 neighbor 52.0.4.2 peer-group PEERs
 neighbor 52.0.5.2 peer-group PEERs
 neighbor 52.0.6.2 peer-group PEERs
 neighbor 52.0.7.2 peer-group PEERs
 neighbor 53.1.1.1 remote-as 1025
 neighbor 53.1.1.1 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
 neighbor PEERs activate
 neighbor PEERs next-hop-self
 neighbor PEERs send-community both
 neighbor PEERs route-map EXPORT_MAP out
 neighbor 52.0.2.2 peer-group PEERs
 neighbor 52.0.3.2 peer-group PEERs
 neighbor 52.0.4.2 peer-group PEERs
 neighbor 52.0.5.2 peer-group PEERs
 neighbor 52.0.6.2 peer-group PEERs
 neighbor 52.0.7.2 peer-group PEERs
 neighbor 53.1.1.1 activate
 neighbor 53.1.1.1 next-hop-self
 neighbor 53.1.1.1 send-community extended
 no auto-summary
 exit-address-family
 !

BB3 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Rack1BB3#sh run | b bgp
router bgp 1025
 no synchronization
 bgp router-id 53.1.1.1
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor PEERs peer-group
 neighbor PEERs remote-as 2048
 neighbor PEERs route-map EXPORT_MAP out
 neighbor 52.1.1.1 remote-as 1025
 neighbor 52.1.1.1 update-source Loopback0
 neighbor 53.0.2.2 peer-group PEERs
 neighbor 53.0.3.2 peer-group PEERs
 neighbor 53.0.4.2 peer-group PEERs
 neighbor 53.0.5.2 peer-group PEERs
 neighbor 53.0.6.2 peer-group PEERs
 neighbor 53.0.7.2 peer-group PEERs
 no auto-summary
 !
 address-family vpnv4
 neighbor PEERs activate
 neighbor PEERs send-community both
 neighbor PEERs route-map EXPORT_MAP out
 neighbor 52.1.1.1 activate
 neighbor 52.1.1.1 next-hop-self
 neighbor 52.1.1.1 send-community extended
 neighbor 53.0.2.2 peer-group PEERs
 neighbor 53.0.3.2 peer-group PEERs
 neighbor 53.0.4.2 peer-group PEERs
 neighbor 53.0.5.2 peer-group PEERs
 neighbor 53.0.6.2 peer-group PEERs
 neighbor 53.0.7.2 peer-group PEERs
 no auto-summary
 exit-address-family
 !

sorry for the long email....

thanx!!!

[]'s
Rodrigo



This archive was generated by hypermail 2.1.4 : Sun Apr 03 2005 - 17:56:52 GMT-3