BGP IPv6 over unnumbered point-to-point

From: Bit Gossip (bit.gossip@chello.nl)
Date: Fri Jan 12 2007 - 18:12:24 ART


R4 has unnumbered point-point interface (Serial0/0.423) over which runs
a eBGP session with R3 using link-local addresses.
R4 has to rewrite the nexthop to a global routable IPv6 address, in this
case borrowed from f0/0 (2002:1:124:40::40) in all adverts to r3.
R3 has no knowledge of 2002:1:124:40::/64 because it is in a different
AS but still install all the prefixes from R4 in this funny recursive
way:

r3#show bgp ipv6 2002:1:124:40::/64
BGP routing table entry for 2002:1:124:40::/64, version 51
Paths: (1 available, best #1, table Global-IPv6-Table)
  Advertised to non peer-group peers:
  2002:1:356:59::59 2002:1:356:69::69
  124
    2002:1:124:40::40 from FE80::423 (4.4.4.4)
      Origin incomplete, metric 0, localpref 100, valid, external, best

And also install it in the RT:

r3#show ipv6 route 2002:1:124:40::/64
IPv6 Routing Table - 25 entries
Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP
       U - Per-user Static route
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS
summary
       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext
2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
B 2002:1:124:40::/64 [20/0]
     via FE80::423, Serial0/0.324

Does it make any sense? :-)
How should a case like this (GP IPv6 over unnumbered point-to-point) be
handled otherwise?

Thanks,
Luca

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

R4

interface FastEthernet0/0
 no ip address
 load-interval 30
 speed 100
 full-duplex
 ipv6 address 2002:1:124:40::40/64
 ipv6 address FE80::40 link-local
 ipv6 enable
!
interface Serial0/0
 description ** frs s1/3 **
 no ip address
 encapsulation frame-relay
 load-interval 30
 clock rate 128000
 no frame-relay inverse-arp
 frame-relay lmi-type cisco
!
interface Serial0/0.423 point-to-point
 bandwidth 64
 ipv6 address FE80::423 link-local
 ipv6 unnumbered FastEthernet0/0
 ipv6 enable
 frame-relay interface-dlci 423
!
router bgp 124
 bgp router-id 4.4.4.4
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor FE80::324 remote-as 356
 neighbor FE80::324 description r3
 neighbor FE80::324 update-source Serial0/0.423
 !
 address-family ipv6
 neighbor FE80::324 activate
 neighbor FE80::324 route-map nh6 out
 redistribute connected
 no synchronization
 exit-address-family
!
route-map nh6 permit 10
 set ipv6 next-hop 2002:1:124:40::40



This archive was generated by hypermail 2.1.4 : Thu Feb 08 2007 - 23:46:56 ART