Installing and Administering Internet Services

Chapter 9 315

Conﬁguring mrouted

Displaying mrouted Routing Tables

There are three routing tables associated with mrouted. They are the

Virtual Interface Table, the Multicast Routing Table, and the

Multicast Routing Cache Table.

The Virtual Interface Table displays topological information for both

physical and tunnel interfaces, the number of incoming and outgoing

packets at each interface, and the value of speciﬁc conﬁguration

parameters, such as metric and threshold, for each virtual interface

(vif).

The Multicast Routing Table displays connectivity information for each

subnet from which a multicast datagram can originate.

The Multicast Routing Cache Table maintained by mrouted is a copy of

the kernel forwarding cache table. It contains status information for

multicast destination group-origin subnet pairs.

These tables are retrieved by sending the appropriate signal to the

mrouted daemon. For retrieving routing tables, mrouted responds to

the following signals:

HUP Restarts mrouted. The conﬁguration ﬁle is reread each

time this signal is evoked.

INT Terminates mrouted gracefully, by sending good-bye

messages to all neighboring routers.

TERM The same as INT.

USR1 Deﬁned as signal 16, dumps the internal routing tables

(Virtual Interface Table and Multicast Routing Table)

to /usr/tmp/mrouted.dump.

USR2 Deﬁned as signal 17, dumps the Multicast Routing

Cache Tables to /usr/tmp/mrouted.cache.

QUIT Dumps the internal routing tables (Virtual Interface

Table and Multicast Routing Table) to stderr (only if

mrouted was invoked with a non-zero debug level).

Signals can be sent to mrouted by issuing the HP-UX kill command at

the HP-UX prompt. For example:

kill -USR1 pid