IP Multicast in a Campus Network
IP Multicast Medium Campus Design
ip msdp cache-sa-state ! ! ip msdp originator-id Loopback0
Creates SA state (S,G). The SA cache entry is created when either MSDP peer has an active source.
Sets RP address in SA messages to be Loopback 0.
Distribution-Layer Switch Configuration
The distribution switches for both building 1 and 2 run PIM-SM on each Layer 3 interface and point to the Anycast RP of 10.6.2.1 (Loopback 1 on both RPs).
The following example shows the multicast configuration for each distribution switch.
ip multicast-routing ! interface VLAN/GigabitEthernet
Enables IP multicast routing globally.
ip pim sparse-mode ip cgmp ! interface Vlanxx
Enables PIM-SM on the interface. Enables CGMP.
description VLANs for other L3 links to Core
ip address 10.0.0.x 255.255. ip pim sparse-mode ! ip pim rp-address 10.6.2.1 ! ip pim spt-threshold infinity ! !
Points to the Loopback 1 address of both core switches.
Reduces multicast state (S,G) from the leaf routers by keeping traffic on the shared tree. (Optional)
!To simplify this example, the HSRP configuration has been omitted.
If the Layer 3 interface connects to a CGMP-enabled switch (3524-PWR), CGMP Server operation must be enabled. If the interface connects to an IGMP snooping enabled router, IP CGMP does not need to be enabled, but PIM must be enabled.
The following example shows how to verify that each distribution switch has established a PIM neighbor relationship.
PIM Neighbor Table
Uptime 2d14h 2d14h 1w1d 1w1d 00:50:59 00:50:59
For information about configuring the Data Center portion of the network for IP multicast, see Chapter 4, “IP Multicast in a Data Center.”
Cisco AVVID Network Infrastructure IP Multicast Design