Dell N1100-ON, Reference Manual

Page: 1573 / 2332

Layer 3 Routing Commands
1573
Default Configuration
This command has no default configuration.
Command Mode
Global Configuration mode
User Guidelines
Use of a multicast routing protocol is recommended (e.g., PIM) when IP
multicast is enabled.
IGMP/MLD snooping may be enabled when IP multicast is enabled. If a
multicast source is connected to a VLAN on which both L3 multicast and
IGMP/MLD snooping are enabled, the multicast source is forwarded to the
mrouter ports that have been discovered when the multicast source is first
seen. If a new mrouter is later discovered on a different port, the multicast
source data is not forwarded to the new port. Likewise, if an existing mrouter
times out or stops querying, the multicast source data continues to be
forwarded to that port. If a host in the VLAN subsequently joins or leaves the
group, the list of mrouter ports is updated for the multicast source and the
forwarding of the multicast source is adjusted. The workaround to this
limitation is to statically configure mrouter ports when enabling IGMP/MLD
snooping in L3 multicast enabled VLANs.
Multicast routing requires IGMP to be enabled to become operationally
enabled. Enabling PIM or DVMRP enables IGMP.
This command enables both IPv4 and IPv6 multicast routing. Multicast
source data is flooded/forwarded by default in the VLAN on which it is
received. For this reason, multi-access VLANs are not recommended for
multicast routing interfaces.
Example
The following example enables IP multicast on the router.
console#configure
console(config)#ip multicast-routing
Command History
User Guidelines updated in release 6.3.5. User Guidelines updated in release
6.4 release.