Dvmrp; The Mbone - 3Com LANPLEX 2500 EXTENDEDPLEX®2500 EXTENDED User Manual

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HAPTER OUTING WITH ULTICAST

DVMRP

The Distance Vector Multicast Routing Protocol (DVMRP) establishes
the multicast delivery path over a series of routing devices. DVMRP is a
simple distance vector routing protocol, similar to the IP Routing
Information Protocol (RIP). Multicast routers exchange distance vector
updates that contain lists of destinations as well as the distance in hops
to each destination. They maintain this information in a routing table.
DVMRP is the current routing protocol used on the Internet Multicast
Backbone (MBONE). Full support of DVMRP allows the LANplex system
to fully establish the delivery path without requiring a direct connection
to a multicast router.

The MBONE

The MBONE is an experimental "Multicast Backbone" network that exists
on the Internet. Users can test multicast applications and technology on
the MBONE without waiting for Internet multicast standards to be set.
You can gain access to the MBONE through any Internet service
provider.
The MBONE routers forward mulitcast packets over an interface or over
a multicast tunnel only if the Time-To-Live (TTL) value present in the
packet is larger than the tunnel's threshold. (See the section "Multicast
Tunnels" on page 6 for more information about tunnels.)
LANplex 2500 systems at revisions earlier than 8.0 support up to 16 IP
multicast tunnels or routing interfaces when connected to the MBONE
network. LANplex 2500 systems at revision 8.0 or later can support up to
32 IP multicast tunnels or routing interfaces when connected to the
MBONE.