3Com 4007, Руководство по внедрению, Страница: 444 / 684

444 C
HAPTER
18: IP M
ULTICAST
R
OUTING
Viewing the
DVMRP
Routing Table
Your module records DVMRP route information in a table that you can
access from the management interface. Your module learns source-based
route information from neighboring DVMRP routers and also advertises
routes that it learns to its neighbors. The routing table does not consider
group membership or prune messages. It simply records path information
it has learned on its own or from other routers, including:
■
Subnetworks from which IP multicast traffic originates
■
Upstream routers (gateway) from which the module should expect to
receive traffic from origin subnetworks
■
Index number of the interface (parent) that is connected to the
upstream router
■
Outgoing interfaces (children) on which it could forward traffic if
group members exist.
The module may never actually process IP multicast traffic from the
sources listed in the routing table. This depends on whether group
members exist on directly-attached subnetworks or on subnetworks from
downstream routers.
See the Command Reference Guide for definitions of the fields of
information and symbols used in the DVMRP route display.
Viewing the
DVMRP Cache
Your module records information about the IP multicast group traffic it
has processed. You can see this information in the DVMRP cache.
To display the DVMRP cache, the module prompts you to enter:
■
A multicast source address
■
A multicast group address
This process limits the cache table to displaying information for one
source-group pair at a time. To display cache information for all
source-group pairs, enter
255.255.255.255
at both prompts.
See the Command Reference Guide for definitions of the fields of
information and symbols used in cache display.