From: Brian Hanson (bhanson@xxxxxxxxx)
Date: Wed Sep 08 1999 - 16:03:31 GMT-3
Edward,
I'll ask the obvious question: Does R5 have "update-source loopback
0" command at the end of your neighbor statements to R3? R5 would
advertise the next hop as the interface that the update went out on
(from R5 to R3). So, if a serial int (ip 172.16.1.1 for example) on
R5 was advertising the BGP routes to R3, the serial address
(172.16.1.1) must be in the IGP table, and reachable from R3.
"update-source loopback 0" will ensure that even though the update
went out the serial int, it would not use the serial int as the update
source address. Rather, it would use the L0 as the source, which you
say IS reachable via IGP.
Hope this helps.
Brian Hanson
Edward Taggart wrote:
I have 2 bgp problems that are driving me crazy. Question 1: I
have 3 routers in the same AS. They are connected as follows:
R3 <---> R2 <---> R5 They all can reach each other fine through
OSPF routes. R5 also has a loopback that is being redistributed
via OSPF. I configured 2 peer statments on all routers providing a
full mesh for the IBGP AS (all sessions show active). The network
that the loopback's address resides in is being advertised to BGP
by R5. When doing a "show ip bgp" it shows up in all 3 routers bgp
table. However, R3 does not advertise the route to an external
AS. When doing a "debug ip bgp update" on R3 I see that it is
complaining that the loopbacks network is not synchronized.
However, the loopbacks network is in the IGP routing table.. Now,
if I remove the peer statements between R3 & R5 and setup R2 with
router-reflector-client statements, R3 advertises the route to the
loopback to the external AS. How I understood it was that routers
in the same AS do not need to be directly connected to their peers,
they just need IP reachability to them and a full mesh peer
configuration (or route a reflector). What am I missing? Qustion
2:If I have an OSPF route and BGP route on a router for the same
network, what would keep the BGP route from injecting itself into
the routing table given that BGP has a lower administrative
distance than OSPF? The following is from a "show ip bgp" command*>
192.192.2.0 132.4.7.5 0 100 0 (1034 1099)
i The following is from a show ip route from the same router as
above:O E2 192.192.2.0/24 [110/20] via 132.4.8.2, 00:37:01,
Serial1 This particular router is in it's own AS so the 192.192.2.0
route is coming in from AS1034 then AS1099.. Any help would be
greatly appreciated. I'm looking through both Caslow's and
Halabi's books and can't seem to find the answer to these problems.
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:21:50 GMT-3