Ip Multicast Dvmrp Tunnels Summary - 3Com 4007 Command Reference Manual

ip multicast dvmrp
tunnels summary
Layer 2
Switching
Modules
Multilayer
Switching
Modules
Summaries key information about DVMRP tunnel end points that are
configured on a Multilayer Switching Module.
Valid Minimum Abbreviation
ip m d t s
Important Considerations
Tunnels enable IP multicast spanning trees to be constructed through
and beyond areas of the network (routers) that do not support IP
multicast routing. The two tunnel end points must lie in different
systems and subnetworks.
The index number shown in the DVMRP tunnel summary display is the
tunnel index number. When you define a DVMRP tunnel, the module
assigns a tunnel index number to it, which is different from the
routing interface index number. Tunnel index numbers provide a way
to identify individual tunnels, which is necessary because multiple
tunnel end points can be configured on the same routing interface.
Tunnel index numbers are also needed so that you can remove tunnels
without removing the interface with which it is associated.
When you remove a tunnel, the module does not dynamically re-order
remaining tunnels in the DVMRP tunnel summary display. For
example, if you had three tunnels with tunnel index numbers 1, 2, and
3, and you then removed tunnel 2, the display lists the remaining
tunnels with their original tunnel index numbers (1 and 3, in this
example). The module assigns tunnel index 2 to the next new tunnel
that you define. After 2 is used, the module can assign tunnel index 4
for the next new tunnel, and so on.
You can define multiple IP multicast tunnel end points on the same
local routing interface, but each must lead to a different remote
interface. If you see two or more identical IP addresses in the
column of the display, verify that the IP addresses in the
Address
column are different.
Remote Address
331
Local