The MDT group address is used by provider edge (PE) routers to form a virtual PIM
“
neighborship
”
for the
MDT. This enables the PEs to communicate with other PEs in the VRF as if they shared a LAN.
When sending customer VRF traffic, PEs encapsulate the traffic in their own (S,G) state, where the G is the
MDT group address, and the S is the MDT source for the PE. By joining the (S,G) MDT of its PE neighbors,
a PE router is able to receive the encapsulated multicast traffic for that VRF.
Although the VRF itself may have many multicast sources sending to many groups, the provider network
needs only to install state for one group per VRF, in other words, the MDT group.
SUMMARY STEPS
1.
configure
2.
multicast-routing
3.
address-family ipv4
4.
nsf
5.
mdt source type interface-path-id
6.
interface all enable
7.
vrf vrf-name
8.
address-family
{
ipv4
}]
9.
mdt default mdt-group-address
10.
mdt data mdt-group-address/prefix-length threshold threshold acl-name
11.
mdt mtu size
12.
interface all enable
13.
commit
DETAILED STEPS
Purpose
Command or Action
configure
Step 1
Enters multicast routing configuration mode.
multicast-routing
Example:
RP/0/RP0/CPU0:router(config)# multicast-routing
Step 2
Enters ipv4 address-family submode.
address-family ipv4
Example:
RP/0/RP0/CPU0:router(config-mcast)#
Step 3
address-family ipv4
Specifies that nonstop forwarding (NSF) maintains the
forwarding state in case of a disruption to a multicast process.
nsf
Example:
RP/0/RP0/CPU0:router(config-mcast-default-ipv4)#
Step 4
Cisco IOS XR Multicast Configuration Guide for the Cisco CRS Router, Release 5.2.x
102
Implementing Multicast Routing on Cisco IOS XR Software
Configuring Multicast VPN