From: Victor Cappuccio (cvictor@protokolgroup.com)
Date: Wed Jun 14 2006 - 01:09:37 ART
Hi Guys,
Why sometimes when checking the BGP Table we can observe routes with a
metric value set and sometimes not
Like in this case:
BGP routing table entry for 0.0.0.0/0, version 7
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Multipath: iBGP
Advertised to non peer-group peers:
145.1.37.7 145.1.53.5 145.1.136.6
Local, (Received from a RR-client)
145.1.136.1 from 145.1.136.1 (150.1.1.1) <<<<< === See there is
no metric value set
Origin IGP, localpref 100, valid, internal, multipath, best
Local, (Received from a RR-client)
145.1.136.6 from 145.1.136.6 (150.1.6.6)
Origin IGP, metric 0, localpref 100, valid, internal, multipath <<<<<
=== the metric is set to 0
R3 is a RR peering with R1 and R6 in the same Ethernet segment
And the configuration in R1 and R6 looks like this:
Rack1R6#show run | be router bgp
router bgp 100
bgp router-id 150.1.6.6
bgp log-neighbor-changes
neighbor 54.1.10.254 remote-as 54
neighbor 145.1.136.3 remote-as 100
!
address-family ipv4
neighbor 54.1.10.254 activate
neighbor 54.1.10.254 dmzlink-bw
neighbor 145.1.136.3 activate
neighbor 145.1.136.3 send-community both
neighbor 145.1.136.3 next-hop-self
neighbor 145.1.136.3 default-originate
neighbor 145.1.136.3 route-map DENYALL out
no auto-summary
no synchronization
exit-address-family
Rack1R1#show run | b router bgp
router bgp 100
bgp router-id 150.1.1.1
bgp log-neighbor-changes
neighbor 145.1.136.3 remote-as 100
neighbor 204.12.1.254 remote-as 54
!
address-family ipv4
neighbor 145.1.136.3 activate
neighbor 145.1.136.3 next-hop-self
neighbor 145.1.136.3 send-community both
neighbor 145.1.136.3 default-originate
neighbor 145.1.136.3 route-map DENYALL out
neighbor 204.12.1.254 activate
neighbor 204.12.1.254 dmzlink-bw
no auto-summary
no synchronization
bgp dmzlink-bw
exit-address-family
Rack1R3#show run | be router bgp
router bgp 100
bgp router-id 150.1.3.3
bgp always-compare-med
bgp log-neighbor-changes
neighbor 145.1.37.7 remote-as 100
neighbor 145.1.53.5 remote-as 200
neighbor 145.1.136.1 remote-as 100
neighbor 145.1.136.6 remote-as 100
maximum-paths ibgp 2
!
address-family ipv4
neighbor 145.1.37.7 activate
neighbor 145.1.37.7 route-map ONLYDEFA out
neighbor 145.1.53.5 activate
neighbor 145.1.53.5 route-map ONLYDEFA out
neighbor 145.1.136.1 activate
neighbor 145.1.136.1 route-reflector-client
neighbor 145.1.136.1 send-community both
neighbor 145.1.136.6 activate
neighbor 145.1.136.6 route-reflector-client
neighbor 145.1.136.6 send-community both
maximum-paths ibgp 2
no auto-summary
no synchronization
bgp dmzlink-bw
network 145.1.136.0 mask 255.255.255.0
aggregate-address 145.1.0.0 255.255.0.0 summary-only
exit-address-family
Any opinion here please
Thanks
Victor.
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:32 ART