mrinfo(1Mtcp)

mrinfo -- display configuration information from a multicast router

Synopsis

/usr/sbin/mrinfo [ -d debug_level ] [ -r retries ] [ -t timeout ] multicast_router

Description

mrinfo attempts to display configuration information from the multicast router multicast_router.

mrinfo sends the IGMP message ASK_NEIGHBORS to the specified multicast router. If the router responds, it includes the version number and a list of neighboring multicast router addresses in the response. If the responding router has a recent multicast version number, mrinfo requests additional information such as metrics, thresholds and flags from the multicast router. Once the multicast router responds, mrinfo displays its configuration on the standard output.

Only root can run mrinfo.

Options

mrinfo understands the following options:

-d debug_level

Set the debug level. If debug_level is greater than the default value of 0, mrinfo displays additional debugging messages. Regardless of the debug level, mrinfo will always output an error message and terminate if an error occurs. Other debug levels are:

1: Print packet warnings to stderr.
2: As level 1 with the addition of printing notification of down networks to stderr.
3: As levels 1 and 2 with the addition of printing notification of all packet timeouts to stderr.

-r retries

Set the limit on the number of times to try querying a neighbor. The default limit is 3 retries.

-t timeout

Set the number of seconds to wait for a neighbor to reply to a query before retrying. The default timeout is 4 seconds.

References

map-mbone(1Mtcp), mrouted(1Mtcp), mtrace(1Mtcp)

Notices

Author

Van Jacobson

Examples

The following is example output from the command mrinfo mbone.phony.dom.net:

   127.148.176.10 (mbone.phony.dom.net) [version 3.3]:
   127.148.176.10 -> 0.0.0.0 (?) [1/1/querier]
   127.148.176.10 -> 127.0.8.4 (mbone2.phony.dom.net) [1/45/tunnel]
   127.148.176.10 -> 105.1.41.9 (momoney.com) [1/32/tunnel/down]
   127.148.176.10 -> 143.192.152.119 (mbone.dipu.edu) [1/32/tunnel]

For each neighbor of the queried multicast router, mrinfo displays the IP address of the queried router, followed by the IP address and name of its neighbor. The information in square brackets shows the metric (cost of connection), and the threshold (multicast TTL). If the queried multicast router has a newer version number, mrinfo also displays the type of route (tunnel or srcrt) and status of the connection (disabled or down).