Service Manual

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
Example of the debug ip msdp Command
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.
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Multicast Source Discovery Protocol (MSDP)