Ip Multicast Dvmrp Tunnels Define - 3Com SuperStack II 9300 Command Reference Manual

ip multicast dvmrp
tunnels define
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For CoreBuilder 9000: Applies to Layer 3 switching modules only.
Defines one end point of a DVMRP tunnel. The other tunnel end point lies
on an IP multicast routing interface on a different system and
subnetwork. One or more unicast routers lie between these tunnel end
points.
Valid Minimum Abbreviation
ip m d t d
Important Considerations
IP multicast tunnels are not required in all networks. Configure a
tunnel only if you need to have IP multicast traffic forwarded through
one or more routers that do not understand IP multicast protocols and
would therefore filter IP multicast packets. Because IP multicast
packets are encapsulated in unicast format at the tunnel entrance
point, the interim routers in the tunnel forward the packets onward
toward the other tunnel exit point.
Think of an IP multicast tunnel end point as being layered on top of a
regular DVMRP routing interface. Therefore, before you can define a
multicast tunnel end point in your system, you must first define at
least one IP virtual LAN (VLAN), define at least one IP interface, and
enable DVMRP on the interface.
The remote tunnel end point must lie on a different system and
subnetwork.
You must define the tunnel on both end points — that is, on both the
local system and the remote system — even though you specify the
address of the remote interface in the local system.
When you define a tunnel with local and remote addresses, the
system automatically assigns the value 1 as both the tunnel metric and
the tunnel TTL threshold, as shown in the IP multicast DVMRP tunnel
summary display. You can change these values through menu options.
IP multicast interfaces and tunnels have similar characteristics, such as
TTL threshold and metric. The characteristics of a tunnel do not have
to match the characteristics of the interface on which it is configured.
You can define multiple tunnel end points on the same local routing
interface in your system, but these tunnels must lead to different
remote routing interfaces.

ip multicast dvmrp tunnels define

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