80
CONFIDENTIAL
26-Jan-04
© 2002 Procket Networks, Inc. All rights reserved.
RPF Check Example
AS1
AS3
MSDP/eMBGP mesh-peering
MBGP Table
Destination
Next Hop
Path
* 172.16.0.2/32
>172.16.3.1
1 i
172.16.0.2/32
172.16.4.1
3 1 i
3.1
4.2
4.1
2.1
MSDP Peers router B
MSDP Peer
State
172.16.3.1
Established
172.16.4.1
Established
RPF rule when MSDP == MBGP peer
Who is the BGP peer adverting this route
BGP Neighbours router B
Peer
AS
172.16.3.1
1
172.16.4.1
3
Src
RPF Success!
Is the AS of the sending MSDP peer
== First AS in RP route?
RP
A
C
B
MSDP SA
4.1
AS 2
ip pim rp-address 172.16.0.2