<br><div class="gmail_quote">On Nov 14, 2007 3:06 AM, Uncle Jim <<a href="mailto:jim@jimani.com">jim@jimani.com</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> /sbin/route add -host <a href="http://229.255.0.1" target="_blank">229.255.0.1</a> dev eth0<br><br>I'm not a multicast expert (or even multicast user) BUT my guess is that the<br>proper command should be:<br><br>
/sbin/route add -net <a href="http://224.0.0.0" target="_blank">224.0.0.0</a> netmask <a href="http://240.0.0.0" target="_blank">240.0.0.0</a> dev eth0<br><br>This is not to say that Monty's command wouldn't work but that this is the
<br>more general command for the <a href="http://224.0.0.0/4" target="_blank">224.0.0.0/4</a> (<a href="http://224.0.0.0" target="_blank">224.0.0.0</a> - <a href="http://239.255.255.255" target="_blank">239.255.255.255</a>
)<br>multicast network.</blockquote><div>But we explicitly do NOT want all multicast traffic to go to the other server. We ONLY want this one multicast IP to go there. Presumably the other server is set up the other way, and in doing this we've defined a multicast IP they can use to talk to each other, but there's nothing else on that subnet, so no other multicast will work there.
<br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br><div class="Ih2E3d"><br>> Put it in /etc/rc.local so it will always be run at boot.
<br><br></div>Monty has spent too much time in the SCO world. On a RedHat system you should<br>use /etc/rc.d/rc.local.</blockquote><div><br>On my RHEL4 box, /etc/rc.local is a link to rc.d/rc.local, so it's all the same, and 5 characters less to (mis)type.
<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> This should allow other multicast packets to stay on eth1.<br><div class="Ih2E3d">
<br></div>I don't know why you would want other multicast packets to go to "The Internet"<br>rather than your local 10. network</blockquote><div>Because something else may need to use <u>routable</u> multicast (not
224/8, but any other multicast IPs), and sending ALL multicast traffic
out eth0 where there is no routing to those other machines will
definitely break that. Remember that the 10. network has exactly two servers and no routers.<br>I'm trying to move the specific routing to
the "non-default" interface, because I just don't know what else needs
to use eth1 with multicast.<br><br> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> but your <a href="http://169.254.0.0" target="_blank">
169.254.0.0</a> traffic, which is<br>defined as "LINKLOCAL", is still not on your "local" network. But since you<br>don't use it, who cares?</blockquote><div>169.254 is a separate UNICAST network that allows DHCP clients to function if they can't obtain a lease.
<br></div><div><br>Your more general route should make any 224/8 multicast on eth1 fail. That might be a problem.<br></div></div><br>