[ntp:hackers] multicast and ntp-dev

mayer at gis.net mayer at gis.net
Tue Nov 16 07:37:40 PST 2004


John,

I'm not convinced that this fix actually fixes it. I'm seeing some
indications
of "packet: bad data 600" messages when I ran it on bridgeport. I set up
bridgeport
to receive broadcast messages and multicast IPv4 and IPV6:
broadcastclient
multicastclient 239.1.1.2
multicastclient FF05::101

both rackety and pogo are sending packets. I see IPv4 multicast for both
rackety and pogo but not IPv6. I'm not sure that there's not a problem
accepting both IPv4 AND IPv6 from the same source but I can't see why
it should matter. Next I'll try turning off IPv4 and see if it synchs
using IPv6. The packets are being received, but it doesn't seem to set
up an IPv6 association.

Danny
----- Original Message Follows -----
> Hi Dave and Danny,
> 
> > I pushed it into my latest code and I'm going to try it out on
> bridgeport.
> 
> I'm sure it will make multicast work, I am using it here and it works.
> I use it on both IPv4 and IPv6. What I don't know is if it will break
> something else or how it will together with other more complex
> configurations.
> 
> Also I think Dave changed the previous mutlicastclient code from
> IBURST to BURST and made some other changes because of some DOS
> problems and we/Dave will have to make sure we don't open that up
> again.
> 
> > >This means that the client server crypto dance must be finished
> > before >the second multicast packet arrives, but because burst mode
> > didn't get >setup properly, it didn't happen.
> > >
> > >So Dave, somewhere between newpeer(), peer_clear() and proto_poll()
> > >the burst mode doesn't get setup properly. My patch is an attempt
> > >to do it, but I don't know if that is correct and the right place.
> > >
> > >===== ntpd/ntp_proto.c 1.186 vs edited =====
> > >--- 1.186/ntpd/ntp_proto.c      2004-11-02 06:05:58 +02:00
> > >+++ edited/ntpd/ntp_proto.c     2004-11-16 05:19:02 +02:00
> > >@@ -1583,6 +1583,9 @@
> > >                peer->filter_epoch[i] = current_time;
> > >        }
> > >
> > >+       if (peer->cast_flags & MDF_BCLNT)
> > >+               peer->burst = NTP_BURST;
> > >+
> > >        /*
> > >        * During initialization use the association count to spread
> > >        out * the polls at one-second intervals. Othersie,
> randomize over
> 
> John
> -- 
> John Hay -- John.Hay at icomtek.csir.co.za / jhay at FreeBSD.org



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