Enterasys SECURESTACK C3, Configuration Manual

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Configuring DVMRP
SecureStack C3 Configuration Guide 20-33
Configuring DVMRP
Purpose
To enable and configure the Distance Vector Multicast Routing Protocol (DVMRP) on an interface.
DVMRP routes multicast traffic using a technique known as Reverse Path Forwarding. When a
router receives a packet, it floods the packet out of all paths except the one that leads back to the
packet’s source. Doing so allows a data stream to reach all VLANs (possibly multiple times). If a
router is attached to a set of VLANs that do not want to receive from a particular multicast group,
the router can send a “prune” message back up the distribution tree to stop subsequent packets
from traveling where there are no members. DVMRP will periodically reflood in order to reach
any new hosts that want to receive from a particular group.
Commands
See also show ip mroute on page 20 ‐ 59 , which can be used to display the IP multicast routing
table.
Enabling DVMRP on an Interface
DVMRP is disabled by default, both globally and on each interface. Enabling DVMRP on a routed
interface requires completing the steps listed in Table 20 ‐ 1 .
* Advanced License Required *
DVMRP is an advanced routing feature that must be enabled with a license key. If you have purchased an
advanced license key, and have enabled routing on the device, you must activate your license as described in
the chapter entitled “Activating Licensed Features” in order
to enable the DVMRP command set. If you wish
to purchase an advanced routing license, contact Enterasys Networks Sales.
Note: An Enterasys Networks Feature Guide document containing an in-depth discussion of
multicast configuration is located on the Enterasys Networks web site:
http://www.enterasys.com/support/manuals/
Note: IGMP must be enabled on all VLANs running DVMRP, and must also be globally enabled
on the SecureStack C3. For details on enabling IGMP, refer to Chapter 13 .
For information about... Refer to page...
ip dvmrp 20-34
ip dvmrp enable 20-34
ip dvmrp metric 20-35
show ip dvmrp 20-35