man mrouted
MROUTED(8) FreeBSD System Manager's Manual MROUTED(8)
NAME
mrouted - IP multicast routing daemon
SYNOPSIS
mrouted [-c config_file] [-d [debug_level]] [-p]
DESCRIPTION
Mrouted is an implementation of the Distance-Vector Multicast Routing
Protocol (DVMRP), an earlier version of which is specified in RFC-1075.
It maintains topological knowledge via a distance-vector routing protocol
(like RIP, described in RFC-1058), upon which it implements a multicast
datagram forwarding algorithm called Reverse Path Multicasting.
Mrouted forwards a multicast datagram along a shortest (reverse) path
tree rooted at the subnet on which the datagram originates. The multi-
cast delivery tree may be thought of as a broadcast delivery tree that
has been pruned back so that it does not extend beyond those subnetworks
that have members of the destination group. Hence, datagrams are not
forwarded along those branches which have no listeners of the multicast
group. The IP time-to-live of a multicast datagram can be used to limit
the range of multicast datagrams.
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демон маршрутизации multicast
если у тебя в сети вещает радио или там мп3 играет
или тебе провайдер выдает поток
или спутник валит
то вот тогда тебе будет нужен mrouted