Table of Contents
Advertisement
cable ip-multicast-echo
cable ip-multicast-echo
To enable IP multicast echo so that the Cisco CMTS can echo multicast packets, use the cable ip-
multicast-echo command in cable interface or subinterface configuration mode. To disable IP multicast
echo, use the no form of this command.
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Cable interface and subinterface configuration
Command History
Release
11.3 XA
12.1(3a) EC
12.1(5)EC
12.2(4)BC1
Usage Guidelines
By default, multicast IP packets that arrive on the upstream at the Cisco CMTS are forwarded on the
appropriate downstream ports so that they are delivered to the other CMs and CPE devices on that
segment of the network. This allows the cable network to behave like a standard Ethernet network in
terms of its handling of multicast IP traffic.
This behavior might not be appropriate for certain applications or networks, so the no cable ip-
multicast-echo command changes this behavior by preventing the forwarding of multicast packets.
Disabling multicast traffic can prevent some types of broadcast storms in which such packets are
repeatedly looped through the network.
To verify if IP multicast echo has been activated or deactivated, enter the show running-config
command and look for the cable interface configuration information. If IP multicast echo has been
enabled (the default configuration), it does not appear in this output. If IP multicast echo has been
disabled, it appears in the output configuration lines as no cable ip-multicast-echo. If you are having
trouble, make sure that you have entered the correct slot and port numbers when you entered cable
interface configuration mode.
On the Cisco uBR10012 router, input access lists are not applied to the multicast traffic that is echoed
Note
on each downstream. To control the echoed multicast traffic, you therefore need to configure an output
access list and apply it to each downstream interface.
Cisco Broadband Cable Command Reference Guide
2-120
cable ip-multicast-echo
no cable ip-multicast-echo
Modification
This command was introduced for Cisco uBR7200 series routers.
The subinterface support was added.
Support was added for Cisco uBR7100 series routers.
Support was added for the Cisco uBR10012 router.
Chapter 2
Cisco CMTS Configuration Commands
OL-1581-08
Advertisement
Table of Contents
