732
Configuring MSDP
Information About MSDP
MSDP Operation
shows MSDP operating between two MSDP peers. PIM uses MSDP as the standard mechanism
to register a source with the RP of a domain. When MSDP is configured, this sequence occurs.
When a source sends its first multicast packet, the first-hop router (
designated router
or RP) directly connected to the
source sends a PIM register message to the RP. The RP uses the register message to register the active source and to
forward the multicast packet down the shared tree in the local domain. With MSDP configured, the RP also forwards a
source-active (SA) message to all MSDP peers. The SA message identifies the source, the group the source is sending
to, and the address of the RP or the originator ID (the IP address of the interface used as the RP address), if configured.
Each MSDP peer receives and forwards the SA message away from the originating RP to achieve peer reverse-path
flooding (RPF). The MSDP device examines the BGP or MBGP routing table to discover which peer is the next hop toward
the originating RP of the SA message. Such a peer is called an
RPF peer
(reverse-path forwarding peer). The MSDP
device forwards the message to all MSDP peers other than the RPF peer. For information on how to configure an MSDP
peer when BGP and MBGP are not supported, see
Configuring a Default MSDP Peer, page 734
.
Figure 92
MSDP Running Between RP Peers
If the MSDP peer receives the same SA message from a non-RPF peer toward the originating RP, it drops the message.
Otherwise, it forwards the message to all its MSDP peers.
The RP for a domain receives the SA message from an MSDP peer. If the RP has any join requests for the group the SA
message describes and if the (*,G) entry exists with a nonempty outgoing interface list, the domain is interested in the
group, and the RP triggers an (S,G) join toward the source. After the (S,G) join reaches the source’s DR, a branch of the
source tree has been built from the source to the RP in the remote domain. Multicast traffic can now flow from the source
across the source tree to the RP and then down the shared tree in the remote domain to the receiver.
MSDP peer
RP + MSDP peer
49885
Receiver
MSDP peer
MSDP SA
MSDP SA
MSDP SA
TCP connection
BGP
Source
Multicast
Register
Peer RPF flooding
PIM sparse-mode
domain
PIM
DR
(S,G) Join
Содержание IE 4000
Страница 12: ...8 Configuration Overview Default Settings After Initial Switch Configuration ...
Страница 52: ...48 Configuring Interfaces Monitoring and Maintaining the Interfaces ...
Страница 108: ...104 Configuring Switch Clusters Additional References ...
Страница 128: ...124 Performing Switch Administration Additional References ...
Страница 130: ...126 Configuring PTP ...
Страница 140: ...136 Configuring CIP Additional References ...
Страница 146: ...142 Configuring SDM Templates Configuration Examples for Configuring SDM Templates ...
Страница 192: ...188 Configuring Switch Based Authentication Additional References ...
Страница 244: ...240 Configuring IEEE 802 1x Port Based Authentication Additional References ...
Страница 274: ...270 Configuring SGT Exchange Protocol over TCP SXP and Layer 3 Transport Configuring Cisco TrustSec Caching ...
Страница 298: ...294 Configuring VLANs Additional References ...
Страница 336: ...332 Configuring STP Additional References ...
Страница 408: ...404 Configuring DHCP Additional References ...
Страница 450: ...446 Configuring IGMP Snooping and MVR Additional References ...
Страница 490: ...486 Configuring SPAN and RSPAN Additional References ...
Страница 502: ...498 Configuring Layer 2 NAT ...
Страница 559: ...555 Configuring Network Security with ACLs How to Configure Network Security with ACLs Creating a Numbered Extended ACL ...
Страница 770: ...766 Configuring IPv6 MLD Snooping Related Documents ...
Страница 930: ...926 Configuring IP Unicast Routing Related Documents ...
Страница 956: ...952 Configuring IPv6 Unicast Routing Configuring IPv6 network 2010 AB8 2 48 network 2010 AB8 3 48 exit address family ...
Страница 976: ...972 Configuring Cisco IOS IP SLAs Operations Additional References ...
Страница 978: ...974 Dying Gasp ...
Страница 990: ...986 Configuring Enhanced Object Tracking Monitoring Enhanced Object Tracking ...
Страница 994: ...990 Configuring MODBUS TCP Displaying MODBUS TCP Information ...
Страница 996: ...992 Ethernet CFM ...
Страница 1030: ...1026 Working with the Cisco IOS File System Configuration Files and Software Images Working with Software Images ...
Страница 1066: ...1062 Using an SD Card SD Card Alarms ...