Try tracing extrahops hops past a non-responding router.
Send the trace query via unicast directly to the multicast router gwy rather than multicasting the query. This must be the last-hop router on the path from the intended source to the receiver.
CAUTION ! ! Versions 3.3 and 3.5 of mrouted will crash if a trace query is received via a unicast packet and mrouted has no route for the source address. Therefore, do not use the -g option unless the target mrouted has been verified to be 3.4 or newer than 3.5.
Use addr as the local interface address (on a multi-homed host) for sending the trace query and as the default for the receiver and the response destination.
Loop indefinitely printing packet rate and loss statistics for the multicast path every 10 seconds (see -S stat_int).
Always request the response using multicast rather than attempting unicast for the last half of the tries.
Set to n the maximum number of hops that will be traced from the receiver back toward the source. The default is 32 hops (infinity for the DVMRP routing protocol).
Print hop addresses numerically rather than symbolically and numerically (saves a nameserver address-to-name lookup for each router found on the path).
Set the maximum number of query attempts for any hop to n. The default is 3.
Do not use the Router-Alert IP option on those requests which need it. Some versions of Ciscos IOS cannot handle multicast traceroutes with IP options, so it may be necessary to use the -O flag if the last-hop router is a Cisco.
Listen passively for multicast responses from traces initiated by others. This works best when run on a multicast router.
Loop indefinitely collecting the path every 10 seconds (see -S stat_int) and printing it when it changes. Do not print any statistics.
Send the trace response to host rather than to the host on which mtrace is being run, or to a multicast address other than the one registered for this purpose (188.8.131.52).
Print a short form output including only the multicast path and not the packet rate and loss statistics.
Change the interval between statistics gathering traces to n seconds (default 10 seconds).
Set the ttl (time-to-live, or number of hops) for multicast trace queries and responses. The default is 127, except for local queries to the "all routers" multicast group which use ttl 1.
"Tunnel statistics" mode; show loss rates for overall traffic. These statistics can be extremely misleading.
Always request the response using unicast rather than attempting multicast first.
Verbose mode; show hop times on the initial trace and statistics display. Also show the route that was used to forward the initial trace.
Set the time to wait for a trace response to n seconds (default 3 seconds).