From: Herbert Maosa (asawilunda@googlemail.com)
Date: Thu Sep 27 2007 - 10:32:26 ART
R4 iBGP peers with R5. R4 and R5 have a common Ethernet Segment which both
are redistributing into BGP. R4 and R5 both EBGP peers with R2 through point
to point Frame relay sub-interfaces. R2 is receiving the Link advertised by
R4 and R5, but it is is preferring the path towards R4. I have eBGP
multipath enabled on R2. I expected that R2 should load balance between R4
and R5 since ALL the BGP attributes are equal and multipath is enabled.
Someone can see what I am not able to see here ?
Below are the BGP configurations of R2,R4 and R5.
*R2*
router bgp 278
no synchronization
bgp router-id 10.10.2.2
bgp log-neighbor-changes
neighbor 183.1.24.4 remote-as 546
neighbor 183.1.25.5 remote-as 546
maximum-paths 6
no auto-summary
interface Serial0/1/0.204 point-to-point
bandwidth 512
ip address 183.1.24.2 255.255.255.0
frame-relay interface-dlci 204
end
!
interface Serial0/1/0.205 point-to-point
bandwidth 512
ip address 183.1.25.2 255.255.255.0
frame-relay interface-dlci 205
end
*R4*
router bgp 546
no synchronization
bgp router-id 10.10.4.4
bgp log-neighbor-changes
redistribute connected route-map NET_45
neighbor 183.1.24.2 remote-as 278
neighbor 183.1.45.5 remote-as 546
no auto-summary
route-map NET_45 permit 10
match interface FastEthernet0/0
*R5*
**
router bgp 546
no synchronization
bgp router-id 10.10.5.5
bgp log-neighbor-changes
redistribute connected route-map NET_45
neighbor 183.1.25.2 remote-as 278
neighbor 183.1.45.4 remote-as 546
no auto-summary
route-map NET_45 permit 10
match interface FastEthernet0/0
*Below is the bgp table on R2*
*Rack1R2#sh ip bgp
*BGP table version is 2, local router ID is 10.10.2.2
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
*> 183.1.45.0/24 183.1.24.4 0 0 546 ?
* 183.1.25.5 0 0 546 ?
Rack1R2#
*Rack1R2#sh ip bgp 183.1.45.0*
BGP routing table entry for 183.1.45.0/24, version 2
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Multipath: eBGP
Advertised to update-groups:
1
546
183.1.24.4 from 183.1.24.4 (10.10.4.4)
Origin incomplete, metric 0, localpref 100, valid, external,
multipath, best
546
183.1.25.5 from 183.1.25.5 (10.10.5.5)
Origin incomplete, metric 0, localpref 100, valid, external, multipath
Rack1R2#
Herbert.
This archive was generated by hypermail 2.1.4 : Sat Oct 06 2007 - 12:01:16 ART