Setup Guide

clear ip msdp peer peer-address
R3(conf)#do show ip msdp peer
Peer Addr: 192.168.0.1
Local Addr: 192.168.0.3(639) Connect Source: Lo 0
State: Established Up/Down Time: 00:04:26
Timers: KeepAlive 30 sec, Hold time 75 sec
SourceActive packet count (in/out): 5/0
SAs learned from this peer: 0
SA Filtering:
Input (S,G) filter: myremotefilter
Output (S,G) filter: none
R3(conf)#do clear ip msdp peer 192.168.0.1
R3(conf)#do show ip msdp peer
Peer Addr: 192.168.0.1
Local Addr: 0.0.0.0(0) Connect Source: Lo 0
State: Inactive Up/Down Time: 00:00:04
Timers: KeepAlive 30 sec, Hold time 75 sec
SourceActive packet count (in/out): 0/0
SAs learned from this peer: 0
SA Filtering:
Input (S,G) filter: myremotefilter
Output (S,G) filter: none
Debugging MSDP
To debug MSDP, use the following command.
● Display the information exchanged between peers.
CONFIGURATION mode
debug ip msdp
R1(conf)#do debug ip msdp
All MSDP debugging has been turned on
R1(conf)#03:16:08 : MSDP-0: Peer 192.168.0.3, sent Keepalive msg
03:16:09 : MSDP-0: Peer 192.168.0.3, rcvd Keepalive msg
03:16:27 : MSDP-0: Peer 192.168.0.3, sent Source Active msg
03:16:38 : MSDP-0: Peer 192.168.0.3, sent Keepalive msg
03:16:39 : MSDP-0: Peer 192.168.0.3, rcvd Keepalive msg
03:17:09 : MSDP-0: Peer 192.168.0.3, sent Keepalive msg
03:17:10 : MSDP-0: Peer 192.168.0.3, rcvd Keepalive msg
03:17:27 : MSDP-0: Peer 192.168.0.3, sent Source Active msg
Input (S,G) filter: none
Output (S,G) filter: none
MSDP with Anycast RP
Anycast RP uses MSDP with PIM-SM to allow more than one active group to use RP mapping.
PIM-SM allows only active groups to use RP mapping, which has several implications:
● traffic concentration: PIM-SM allows only one active group to RP mapping which means that all traffic for the group must,
at least initially, travel over the same part of the network. You can load balance source registration between multiple RPs
by strategically mapping groups to RPs, but this technique is less effective as traffic increases because preemptive load
balancing requires prior knowledge of traffic distributions.
● lack of scalable register decasulation: With only a single RP per group, all joins are sent to that RP regardless of
the topological distance between the RP, sources, and receivers, and data is transmitted to the RP until the SPT switch
threshold is reached.
● slow convergence when an active RP fails: When you configure multiple RPs, there can be considerable convergence
delay involved in switching to the backup RP.
Anycast RP relieves these limitations by allowing multiple RPs per group, which can be distributed in a topologically significant
manner according to the locations of the sources and receivers.
474
Multicast Source Discovery Protocol (MSDP)