From: Hunt Lee (ciscoforme3@xxxxxxxxxxxx)
Date: Fri Jun 21 2002 - 22:23:26 GMT-3
Hey all,I'm probably missing some fairly simple concept here. I have setup 4 r
outers as follows:- RTB /RTD --- RTA
\ RTC Both RTB & RTC are connected (via Eth) to a network calle
d 172.17.1.0 /24.RTA & RTD are both in AS2RTB & RTC are both in AS1The connecti
on between RTA & RTD is via EthernetRouterA#sh ip bgpBGP table version is 9, lo
cal router ID is 25.25.25.2Status codes: s suppressed, d damped, h history, * v
alid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incomplete Netw
ork Next Hop Metric LocPrf Weight Path*> 10.1.1.0/30 1
0.1.1.2 0 0 1 i* 10.1.2.2
0 1 i*> 10.1.2.0/30 10.1.1.2
0 1 i* 10.1.2.2 0 0 1 i*>
25.25.25.0/24 0.0.0.0 0 32768 i*> 172.17.1.0/24
10.1.1.2 0 0 1 i* 10.1.2.2
0 0 1 iRouterA#sh running-config router bgp 2 network
25.25.25.0 mask 255.255.255.0 neighbor 10.1.1.2 remote-as 1 neighbor 10.1.2.2 r
emote-as 1 neighbor 25.25.25.1 remote-as 2 maximum-paths 6When I lookup RTD's B
GP table (shown below), for the route 172.17.1.0/24, instead of via 10.1.1.2 or
10.1.2.2, it is 25.25.25.2. Ok - here's what I'm confused about. Since I tho
ught that in EBGP peering, the next hop is usually the IP address of the neighb
or that announced the route, but IBGP peering preserve the Next-hop attribute l
earned from EBGP peers. So in the case, if I haven't use next-hop-self on RTA,
I would think the EBGP next hop in RTD's BGP table would be either 10.1.1.2 or
10.1.2.2, but why is the EBGP next-hop is 25.25.25.2?RouterD#sh ip bgpBGP tabl
e version is 6, local router ID is 172.16.0.2Status codes: s suppressed, d damp
ed, h history, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? -
incomplete Network Next Hop Metric LocPrf Weight Path*>i
10.1.1.0/30 25.25.25.2 0 100 0 1 i*>i10.1.2.0/30
25.25.25.2 100 0 1 i*>i25.25.25.0/24 25.25.25.2
0 100 0 i *>i172.17.1.0/24 25.25.25.2 0
100 0 1 i
---------------------------------
SOLD.com.au- Find yourself a bargain!
This archive was generated by hypermail 2.1.4 : Tue Jul 02 2002 - 08:12:40 GMT-3