mrinfo uses the ASK_NEIGHBORS IGMP message to the specified multicast router. If this multicast router responds, the version number and a list of their neighboring multicast router addresses is part of that response. If the responding router has a recent multicast version number, then mrinfo requests additional information such as metrics, thresholds, and flags from the multicast router. Once the specified multicast router responds, the configuration is displayed to the standard output.
"-d" option sets the debug level. When the debug level is greater than the default value of 0, addition debugging messages are printed. Regardless of the debug level, an error condition, will always write an error message and will cause mrinfo to terminate. Non-zero debug levels have the following effects:
"-r retry_count" sets the neighbor query retry limit. Default is 3 retry.
"-t timeout_count" sets the number of seconds to wait for a neighbor query reply. Default timeout is 4 seconds.
mrinfo mbone.phony.dom.net 127.148.176.10 (mbone.phony.dom.net) [version 3.3]: 127.148.176.10 -\*[Gt] 0.0.0.0 (?) [1/1/querier] 127.148.176.10 -\*[Gt] 127.0.8.4 (mbone2.phony.dom.net) [1/45/tunnel] 127.148.176.10 -\*[Gt] 105.1.41.9 (momoney.com) [1/32/tunnel/down] 127.148.176.10 -\*[Gt] 143.192.152.119 (mbone.dipu.edu) [1/32/tunnel]
For each neighbor of the queried multicast router, the IP of the queried router is displayed, followed by the IP and name of the neighbor. In square brackets the metric (cost of connection), the treashold (multicast ttl) is displayed. If the queried multicast router has a newer version number, the type (tunnel, srcrt) and status (disabled, down) of the connection is displayed.