Go CCIE Go!! - A Cisco Certified Internetwork Expert

Afternoon Team; my first post, failed my lab in May06 and revising again for attempt 2 - I can’t see this problem in the archives, so here I go:
Situation: I am revising confederations (”confeds”). I have 5 rtrs (A,B,C,2,1) wired in that order connected b2b via serial or Eth VLANs. Each rtr is running BGP, with each natively advertising a single /32 from a loopback into BGP using “network X mask X”. Goal: all rtrs to have all 5 /32s in the BGP table.
3 of the rtrs (B,C,2) are to present themselves externally as AS#70, however only rtrs B+C may use a “confederation identifier X” statement. Rtr 2 peers with the confeds and has “confederation peer 101 102″, but cannot exist within a sub-AS and must not use “confederation identifier X” - the goal of this lab is to emulate a large AS where only part of the network uses confeds, or is partially migrated to use confeds - Rtr 2 is the device we are trying to emulate as not yet being migrated to a confed but is part of the overall AS#70.
‘Rtr name’ #AS [confed sub-AS]
Rtr ‘A’ #26 - Rtr ‘B’ #70 [101] - Rtr ‘C’ #70 [102] - Rtr ‘2′ #70 - Rtr ‘1′ #15
Rtr name - /32 prefix (loopback) A - 21.21.21.21 B - 67.67.67.67 C - 87.87.87.87 2 - 34.34.34.34 1 - 19.19.19.19
Problem: all routers peer perfectly, no error msgs, etc. The problem is to do with route propagation. All routes advertised by rtrs A+B+C are passed to all rtrs, however routes originating on rtr 2 or 1, are not accepted by rtr C.
“debug ip bgp updates” on Rtr C (from routes received from Rtr 2 [the non-confed router in AS70]) show: Rtr_C_# *Mar 1 05:47:30.906: BGP(0): 2.2.2.2 rcv UPDATE w/ attr: nexthop 2.2.2.2, origin i, localpref 100, metric 76, originator 0.0.0.0, path 70, community , extended community *Mar 1 05:47:30.906: BGP(0): 2.2.2.2 rcv UPDATE about 34.34.34.34/32 — DENIED due to: AS-PATH contains our own AS;
*Mar 1 05:47:30.906: BGP(0): 2.2.2.2 rcv UPDATE w/ attr: nexthop 2.2.2.2, origin i, localpref 100, metric 76, originator 0.0.0.0, path 70 15, community , extended community *Mar 1 05:47:30.910: BGP(0): 2.2.2.2 rcv UPDATE about 19.19.19.19/32 — DENIED due to: AS-PATH contains our own AS; Rtr_C_#
I understand why this is happening - AS loop prevention on rtr C analysing the AS path on routes passed from rtr 2, and seeing its own AS, rejects the route. I can’t believe this situation hasn’t existed in the real world, so was wondering if there is something I am overlooking to make this work.
Any help would be greatly appreciated - thanks for your support,
best regards,
Neil Moss www.smogey.net
Partial configs for completeness:
Rtr A router bgp 26 network 21.21.21.21 mask 255.255.255.255 neighbor 9.0.0.1 remote-as 70
Rtr B router bgp 101 bgp confederation identifier 70 bgp confederation peers 70 102 network 67.67.67.67 mask 255.255.255.255 neighbor 9.0.0.2 remote-as 26 neighbor 9.0.0.10 remote-as 102
Rtr C router bgp 102 bgp confederation identifier 70 bgp confederation peers 70 101 network 87.87.87.87 mask 255.255.255.255 neighbor 2.2.2.2 remote-as 70 neighbor 9.0.0.9 remote-as 101
Rtr 2 router bgp 70 bgp confederation peers 101 102 network 34.34.34.34 mask 255.255.255.255 neighbor 2.2.2.1 remote-as 102 neighbor 3.0.0.1 remote-as 15
Rtr 1 router bgp 15 network 19.19.19.19 mask 255.255.255.255 neighbor 3.0.0.2 remote-as 70