Cisco CRS Series - Understanding Enabling and Disabling Interfaces; Multicast Routing Information Base; Multicast Forwarding Information Base

RP/0/RP0/CPU0:router(config)# router igmp
RP/0/RP0/CPU0:router(config-igmp)# vrf default
RP/0/RP0/CPU0:router(config-igmp)# interface GigabitEthernet0/6/0/0
RP/0/RP0/CPU0:router(config-igmp-name-if)# router enable
For related information, see Understanding Enabling and Disabling Interfaces, on page 68
Understanding Enabling and Disabling Interfaces
When the Cisco IOS XR Software multicast routing feature is configured on your router, by default, no
interfaces are enabled.
To enable multicast routing and protocols on a single interface or multiple interfaces, you must explicitly
enable interfaces using the interface command in multicast routing configuration mode.
To set up multicast routing on all interfaces, enter the interface all command in multicast routing configuration
mode. For any interface to be fully enabled for multicast routing, it must be enabled specifically (or be default)
in multicast routing configuration mode, and it must not be disabled in the PIM and IGMP/MLD configuration
modes.
For example, in the following configuration, all interfaces are explicitly configured from multicast routing
configuration submode:
RP/0/RP0/CPU0:router(config)# multicast-routing
RP/0/RP0/CPU0:router(config-mcast)# interface all enable
To disable an interface that was globally configured from the multicast routing configuration submode, enter
interface configuration submode, as illustrated in the following example:
RP/0/RP0/CPU0:router(config-mcast)# interface GigabitEthernet0pos 0/1/0/0
RP/0/RP0/CPU0:router(config-mcast-default-ipv4-if)# disable
Multicast Routing Information Base
The Multicast Routing Information Base (MRIB) is a protocol-independent multicast routing table that
describes a logical network in which one or more multicast routing protocols are running. The tables contain
generic multicast routes installed by individual multicast routing protocols. There is an MRIB for every logical
network (VPN) in which the router is configured. MRIBs do not redistribute routes among multicast routing
protocols; they select the preferred multicast route from comparable ones, and they notify their clients of
changes in selected attributes of any multicast route.
Multicast Forwarding Information Base
Multicast Forwarding Information Base (MFIB) is a protocol-independent multicast forwarding system that
contains unique multicast forwarding entries for each source or group pair known in a given network. There
is a separate MFIB for every logical network (VPN) in which the router is configured. Each MFIB entry
resolves a given source or group pair to an incoming interface (IIF) for reverse forwarding (RPF) checking
and an outgoing interface list (olist) for multicast forwarding.
Cisco IOS XR Multicast Configuration Guide for the Cisco CRS Router, Release 5.2.x
68
Implementing Multicast Routing on Cisco IOS XR Software
Understanding Enabling and Disabling Interfaces