Subject: Re: Verify DVMRP routes?

From: Bill Fenner <[email-masked]>
Date: Thu, 27 Mar 1997 15:58:15 PST

>How can I as a site connected to the MBONE verify that all see my routes?

You can use third-party mtrace's.  You have to select the target
of the mtrace carefully, due to a too-strict algorithm in mrouted
3.8, but for example:

dartvader% mtrace -g dec3800-2-fddi-0.SanFrancisco.mci.net
mtrace: WARNING: no multicast group specified, so no statistics printed
* Mtrace from 204.162.228.2 to 204.70.158.61 via group 224.2.0.1
Querying full reverse path... 
  0  dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61)
 -1  dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61)  DVMRP  thresh^ 1  
 -2  mbone.nsi.nasa.gov (192.203.230.241)  DVMRP  thresh^ 64  
 -3  ames.dart.net (192.52.195.128)  DVMRP  thresh^ 32  
 -4  parc.dart.net (140.173.144.2)  DVMRP  thresh^ 1  
 -5  dartvader (204.162.228.2)
Round trip time 48 ms; total ttl of 67 required.

mtrace 5.1 introduced the command-line defaults as above; if you're
using an older mtrace you have to specify

mtrace -g <place> <me> <place>, e.g.

dartvader% mtrace -g dec3800-2-fddi-0.SanFrancisco.mci.net dartvader dec3800-2-fddi-0.SanFrancisco.mci.net

but it's much easier to just upgrade to mtrace 5.1 .

A "no route" reply is a definite negative indication:

* Mtrace from 127.0.0.1 to 204.70.158.61 via group 224.2.0.1
Querying full reverse path... 
  0  dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61)
 -1  dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61)  No route
Round trip time 30 ms; total ttl of 2 required.

but a timeout gives no information; it could mean any number of things
(most likely is that you need to use a different target to use for your
third-party mtrace).

  Bill