Information Technology Reference
In-Depth Information
Example 11-25
Provider B Router Configuration (Continued)
!
interface Serial4/0
ip address 10.1.3.2 255.255.255.252
ip pim sparse-mode
!
router bgp 200
...
network 20.1.0.3 mask 255.255.255.255
neighbor 10.1.3.1 remote-as 65000
!
address-family ipv4 multicast
...
neighbor 10.1.3.1 activate
network 20.1.0.3 mask 255.255.255.255
exit-address-family
!
ip pim rp-address 20.1.0.3
ip msdp peer 10.1.3.1 connect-source Serial4/0
!
The customer has MP-BGP sessions and MSDP sessions with both providers so that he can
use whichever upstream ISP is closest to the multicast source, based on standard BGP path
selection. The use of multiple MSDP peers requires the use of MP-BGP for MSDP SA RPF
checking. The customer with two e(m)BGP sessions performs peer-RPF based on Rule 2.
Interdomain Connections
The interdomain MSDP sessions are handled by having the MSDP peering session form
between the remote domain's RP and the border router with the connection to the remote
domain. The border routers then MSDP peer with the RP, as shown in Figure 11-32.
The general rule of thumb for deploying MSDP is to run (m)BGP and ensure a congruent
peering topology. This ensures that failures are handled correctly to ensure continued
connectivity when external peering sessions fail.
