Information Technology Reference
In-Depth Information
loop can be formed with three routers that are peers with each other in a full mesh, which
is three MSDP peering sessions. If each MSDP peering session is configured as a different
mesh group peer, a loop forms. The mesh group definitions are local to the router.
Route Reflection Issues
The use of route reflection can create problems with MSDP SA RPF checking. This is
because the BGP peering addresses are used for the RPF check. Figure 11-26 shows how
route reflection can interfere with MSDP SA RPF checking by diverging the (m)BGP and
MSDP peering topology.
Figure 11-26
Route Reflection's Impact on MSDP SA RPF
Source
ISP 2
RP
BGP Peer
MSDP Peer
SA Message
ISP 1
RP
The main issue to watch out for with route reflection and MSDP peering is that the MSDP
peering session does not correspond with the iBGP peer unless the RR is also part of the
MSDP topology. In this case, the No BGP Session RPF rule is used instead of the iBGP
