[Spread-users] Multicast Configuration for multi-site

Jonathan Stanton jonathan at cnds.jhu.edu
Tue Aug 12 18:25:37 EDT 2003

Spread does not support a configuration with one multicast address for
multiple 'segments'. Also the version we distribute limits the
propagation of ip-multicast datagrams to only a local network by setting
the TTL to 1 (so the datagram will be dropped when it crosses a router).
Spread is designed to handle the dissemination of messages between sites

I've never tried it, but if you want to experiment you could try
using a configuration with one segment including all of the machines
that can be reached by ip-multicast (over the wan) and changing the code
in data_link.c on line 85 (shown below)

		ttl_val = 1;
        	if (setsockopt(chan, IPPROTO_IP, IP_MULTICAST_TTL,
(void *)&ttl_val, 

to set a larger ttl (like 15), recompile the daemon and see what
happens. If you do experiment I'd love to hear the results (both whether
or not it works and how fast it is compared to a configuration with
multiple sites, one for each lan using local area ip-multicast.



On Tue, Aug 12, 2003 at 05:15:07PM -0400, Administrator wrote:
> Does anyone know how to set the spread config file to have one multicast address that covers multi sites?
> In mbone (multicast backbone), you can configure a process (router) to bridge between sites.
> Thanks,
> Jim
> _______________________________________________
> Spread-users mailing list
> Spread-users at lists.spread.org
> http://lists.spread.org/mailman/listinfo/spread-users

Jonathan R. Stanton         jonathan at cs.jhu.edu
Dept. of Computer Science   
Johns Hopkins University    

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