hi there! After reading this list archives, and after playing around with the broadcast option in ntp.conf to enable multicast in a ntp server,I'm unable to do a couple of things that should work without problems.
I'm using servers that come with three network cards. Our network topology uses two of them to send data, and the third one is used for server management. The problem is that it doesn't matter what I do, multicast group is always sended through the last configured nic (eth2). My boxes run linux, and multicast routes are configured: ifconfig eth0 214.25.250.1 ifconfig eth1 214.25.249.1 ifconfig eth2 172.88.1.1 route add -net 225.25.250.0 mask 255.255.255.0 dev eth0 route add -net 225.25.249.0 mask 255.255.255.0 dev eth1 route add default gw 172.88.1.100 ntp.conf: broadcast 225.25.250.123 Running tcpdump shows that multicat packets output through eth2... I'm running no mcast daemon. Since ntpd asks the kernel the multicast route, something is going wrong since it is outputing data to the wrong interface, with the wrong source address. If ntpd doesn't rely on the routing tables to output its data, it should let the user specify the source ip of the outgoing multicast packet, so it will leave the box using the correct interface. I was thinking about the possibility of modifying ntpd, to add a "source ip" and a "destination interface" to the broadcast directive. Maybe a better approach is to use a multicast routing daemon? There are not plenty of them... I've only found one, smcroute, which insert static multicast routes in kernel. mrouted no longer exists, zebra is out... Could someone bring some light to this, thanks in advance! -- -- Use of a keyboard or mouse may be linked to serious injuries or disorders. diego dot torres at gmail dot com - Madrid / Spain _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
