Subject: Multicast routing

From: Gerard Hickey <[email-masked]>
Date: Wed, 22 Jul 1998 08:33:02 -0400

Does anyone have any experience configuring mrouted when variable length
subnet masks are used? 

I have a problem getting multicast packets between two sites that use
different subnet masks. I can get the mrouted processes to see one
another, but they will not pass any data back and forth. 

There does not seem to be a great deal of information on how
mrouted.conf works. Is there a indepth paper on what each configuration
parameter is doing? 

Thanks.
--
Gerard Hickey                             email: [email-masked]
National Semiconductor Corporation        phone: +1 207 541 6101
Advance Development Center, MS 03-03      fax:   +1 207 541 6108
5 Foden Road, South Portland, Maine 04106-1706

---

From: Bill Fenner <[email-masked]>
Date: Wed, 22 Jul 1998 09:22:12 PDT

>Does anyone have any experience configuring mrouted when variable length

If the subnets do not overlap, everything should just work.  If the
subnets do overlap (which often happens when people are doing proxy
ARP for unicast), you can use the "phyint foo netmask" command to
tell mrouted what the effective netmask for multicasts should be.
You can also use the "altnet" command to list other subnets that are
connected to the wire.

>another, but they will not pass any data back and forth. 

If you "kill -USR1 `cat /etc/mrouted.pid`", does the /usr/tmp/mrouted.dump
file contain the routes for both ends of the tunnel?  If you
"kill -USR2 `cat /etc/mrouted.pid`", is there an entry for the
host that is sending the traffic and the group that it's sending
to?

This may seem silly, but is the traffic being sourced with a TTL greater
than 1, so that it may be forwarded?

>mrouted.conf works. Is there a indepth paper on what each configuration

The 3.9-beta3 man page has somewhat more in-depth explanations of each
option.

  Bill