Information Technology Reference
In-Depth Information
Figure 11-21
Successful eBGP-Based MSDP SA RPF
Source
ISP 3
ISP 2
R1
R2
BGP Peer
MSDP Peer
ISP 4
ISP 5
SA Message
R3
R4
ISP 1
R5
When the MSDP peer address is the same as the address of an EBGP peer, the RPF function
is to ensure that the SA is received from the MSDP peer in the AS from which the best path
to the originating RP is received. In Example 11-13, the first AS in the AS_PATH to the
originating RP is 4. The MSDP peer from which the SA was received is 10.3.1.10, which
is also the address of the EBGP peering with AS 4.
Example 11-13
mBGP Information for the Originating RP
R5#show ip mbgp 10.1.0.1
BGP routing table entry for 10.1.0.1/32, version 2
Paths: (2 available, best #2, table Default-MBGP-Routing-Table)
Advertised to non peer-group peers:
10.3.1.5
5 4 2 3
10.3.1.5 from 10.3.1.5 (10.1.0.3)
Origin IGP, localpref 100, valid, external
4 2 3
10.3.1.10 from 10.3.1.10 (10.1.0.4)
Origin IGP, localpref 100, valid, external, best
