Foundry Switch and Router Installation and Configuration Guide
18 - 30
December 2000
Configuring Multicast Source Discovery Protocol (MSDP)
The Multicast Source Discovery Protocol (MSDP) is used by Protocol Independent Multicast (PIM) Sparse routers
to exchange routing information for PIM Sparse multicast groups across PIM Sparse domains. Routers running
MSDP can discover PIM Sparse sources that are in other PIM Sparse domains.
PIM Sparse routers use MSDP to register PIM Sparse multicast sources in a domain with the Rendezvous Point
(RP) for that domain.
Figure 18.4 shows an example of some PIM Sparse domains. For simplicity, this example show only one
Designated Router (DR), one group source, and one receiver for the group. Only one PIM Sparse router within
each domain needs to run MSDP.
Figure 18.4
PIM Sparse domains joined by MSDP routers
In this example, the source for PIM Sparse multicast group 232.0.1.95 is in PIM Sparse domain 1. The source
sends a packet for the group to its directly attached DR. The DR sends a Group Advertisement message for the
group to the domain’s RP. The RP is configured for MSDP, which enables the RP to exchange source information
with other PIM Sparse domains by communicating with RPs in other domains that are running MSDP.
The RP sends the source information to each of its peers by sending a Source Active message. The message
contains the IP address of the source, the group address to which the source is sending, and the IP address of the
RP interface with its peer. In this example, the Source Active message contains the following information:
•
Source address: 206.251.14.22
•
Group address: 232.1.0.95
•
RP address: 206.251.17.41
Rendezvous Point (RP)
PIM Sparse Domain 3
Rendezvous Point (RP)
Receiver for Group
232.1.0.95
PIM Sparse Domain 4
Rendezvous Point (RP)
PIM Sparse Domain 2
Source for Group
232.1.0.95
PIM Sparse Domain 1
Designated Router (DR)
206.251.14.22
Source Advertisement message
1. DR receives traffic from source
and registers source with RP.
2. RP sends SA message
through MSDP to its MSDP
peers in other PIM Sparse
domains.
4. When SA caching is enabled,
the RP immediately responds to
Join messages from receivers.
Otherwise, the RP and receiver
must wait for the next SA message
for the group.
3. RP that receives the SA
floods the SA to all its MSDP
peers, except the one that sent
the SA.
Rendezvous Point (RP)
206.251.17.41
Summary of Contents for Switch and Router
Page 2: ...December 2000 Copyright 2000 by Foundry Networks Inc ...
Page 26: ...Foundry Switch and Router Installation and Configuration Guide xxvi December 2000 ...
Page 64: ...Foundry Switch and Router Installation and Configuration Guide 2 34 December 2000 ...
Page 162: ...Foundry Switch and Router Installation and Configuration Guide 5 38 December 2000 ...
Page 196: ...Foundry Switch and Router Installation and Configuration Guide 6 34 December 2000 ...
Page 208: ...Foundry Switch and Router Installation and Configuration Guide 7 12 December 2000 ...
Page 236: ...Foundry Switch and Router Installation and Configuration Guide 8 28 December 2000 ...
Page 258: ...Foundry Switch and Router Installation and Configuration Guide 9 22 December 2000 ...
Page 420: ...Foundry Switch and Router Installation and Configuration Guide 13 32 December 2000 ...
Page 442: ...Foundry Switch and Router Installation and Configuration Guide 14 22 December 2000 ...
Page 554: ...Foundry Switch and Router Installation and Configuration Guide 15 112 December 2000 ...
Page 574: ...Foundry Switch and Router Installation and Configuration Guide 16 20 December 2000 ...
Page 626: ...Foundry Switch and Router Installation and Configuration Guide 17 52 December 2000 ...
Page 682: ...Foundry Switch and Router Installation and Configuration Guide 18 56 December 2000 ...
Page 826: ...Foundry Switch and Router Installation and Configuration Guide 20 20 December 2000 ...
Page 994: ...Foundry Switch and Router Installation and Configuration Guide 26 10 December 2000 ...
Page 1004: ...Foundry Switch and Router Installation and Configuration Guide B 6 December 2000 ...
Page 1044: ...Foundry Switch and Router Installation and Configuration Guide C 40 December 2000 ...
Page 1048: ...Foundry Switch and Router Installation and Configuration Guide D 4 December 2000 ...
Page 1070: ...Foundry Switch and Router Installation and Configuration Guide Index 18 December 2000 ...