[ntp:questions] multicast - wrong interface
Richard B. gilbert
rgilbert88 at comcast.net
Sat Feb 17 16:26:37 UTC 2007
> Hello !
> My NTP server sends all multicast traffic from eth0 and I don't
> know how to configure it to send it to the LAN connected via eth2.
> The details are below. Could you please give me some
> hints or help ?
> Thank you
> - - - - - -
> In the ntp.conf there is:
> broadcast 188.8.131.52 key 145 ttl 3
> and the linux kernel has a route for class D addresses, it uses eth2:
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 184.108.40.206 * 240.0.0.0 U 0 0 0 eth2
> but the output from ntp -D2 shows, that NTP has chosen eth0 (fd #18) and
> not eth2 (verified with tcpdump):
> created interface #2: fd=18, bfd=-1, name=eth0, flags=0x19, scope=0,
> ifindex=0, sin=217.XX.XXX.XX, bcast=217.XX.XXX.223,, mask=255.255.255.224,
> created interface #3: fd=19, bfd=-1, name=eth2, flags=0x19, scope=0,
> ifindex=0, sin=192.168.XX.XX, bcast=192.168.XX.255,, mask=255.255.255.0,
> MCAST ***** sendpkt(fd=18 dst=220.127.116.11, src=217.XX.XXX.XX, ttl=96, len=68)
> (BTW, why is ttl=96 and not 3 ? But that's not the problem.)
> questions mailing list
> questions at lists.ntp.isc.org
Try going with the flow. If ntpd wants to multicast via eth0, then
connect eth0 to the network you want to multicast to. Reassign another
interface to do whatever eth0 was doing.
It may be a lot of work but you'll get much faster results than you
would by waiting for a major redesign of ntpd networking.
Alternatively, you could try hacking the code yourself and contributing
any solution you find.
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