3Com CoreBuilder 3500, Command Reference Manual

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ip multicast dvmrp routeDisplay 517
ip multicast dvmrp
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routeDisplay
For CoreBuilder 9000: Applies to Layer 3 switching modules only.
Displays IP multicast route information that your system has learned from
using the Distance-Vector Multicast Routing Protocol (DVMRP). The
system uses this information to forward IP multicast traffic that it receives.
Valid Minimum Abbreviation
ip m d r
Fields in the IP Multicast DVMRP Route Display
Field Description
Origin IP address of the subnetwork that contains an IP multicast
source, followed by a forward slash and subnetwork
mask.
Gateway IP address of the routing interface that lies upstream of
the local system on the path back towards an IP multicast
source. If the source subnetwork is connected directly to
your system, this field contains a dash (--).
Metric Number of hops from your system back to the origin
subnetwork. This value is
not
the DVMRP interface or
tunnel metric, which are shown under
Metric
in other
displays.
Occasionally, instead of a numeric value, you may see
NR
,
meaning “network unreachable.” Your system may have
trouble computing the hop count because of factors such
as an upstream router being temporarily congested. This
condition is usually resolved in a short period of time.
Tmr Amount of time (in seconds) since each entry was last
reset.
Parent The interface that connects to the upstream router
(Gateway). Because DVMRP forms a loopless spanning
tree to reach all hosts for a given IP multicast group, your
system always chooses a single parent interface. Either an
I
or a
T
precedes the index number. An
I
indicates that
the index is an interface index number. A
T
indicates that
the index is a tunnel index number.
Children Interfaces that communicate with downstream routers or
local subnetworks. The system forwards incoming IP
multicast traffic through these interfaces. Either an
I
or a
T
precedes each index number. An
I
precedes an
interface index number. A
T
precedes a tunnel index
number.