mrouted.1m (2010 09)

mrouted(1M) mrouted(1M)

The cache tables look like this:

Multicast Routing Cache Table (147 entries)

Origin Mcast-group CTmr Age Ptmr IVif Forwvifs

13.2.116/22 224.2.127.255 3m 2m - 0 1

>13.2.116.19

>13.2.116.196

138.96.48/21 224.2.127.255 5m 2m - 0 1

>138.96.48.108

128.9.160/20 224.2.127.255 3m 2m - 0 1

>128.9.160.45

198.106.194/24 224.2.135.190 9m 28s 9m 0P

>198.106.194.22

Each entry is characterized by the origin subnet number, mask, and the destination multicast group. The

CTmr ﬁeld indicates the lifetime of the entry. The entry is deleted from the cache table when the timer

decrements to zero. The Age ﬁeld is the time since this cache entry was originally created. Since cache

entries get refreshed if trafﬁc is ﬂowing, routing entries can grow very old. The Ptmr ﬁeld is simply a

dash if no prune was sent upstream, or the amount of time until the upstream prune will time out. The

Ivif ﬁeld indicates the incoming vif for multicast packets from that origin. Each router also maintains a

record of the number of prunes received from neighboring routers for a particular source and group. If

there are no members of a multicast group on any downward link of the multicast tree for a subnet, a

prune message is sent to the upstream router. They are indicated by a

P after the vif number. The

Forwvifs ﬁeld shows the interfaces along which datagrams belonging to the source-group are forwarded.

p indicates that no datagrams are being forwarded along that interface. An unlisted interface is a leaf

subnet with no members of the particular group on that subnet. A b on an interface indicates that it is a

boundary interface; that is, trafﬁc will not be forwarded on the scoped address on that interface. An addi-

tional line with a > as the ﬁrst character is printed for each source on the subnet. Note that there can be

many sources in one subnet.

AUTHOR

mrouted was developed by Steve Deering, Ajit Thyagarajan, Bill Fenner.

FILES

/etc/mrouted.conf

/var/run/mrouted.pid

/var/tmp/mrouted.cache

/var/tmp/mrouted.dump