[ntp:questions] NTP does not reply to IP addresses that start with 69

Ronan Flood usenet at umbral.org.uk
Wed Apr 2 15:17:20 UTC 2008


On Tue, 1 Apr 2008 12:44:17 -0400, "Ray" <nospam.mail at nrc.ca> wrote:

> input_handler: if=2 fd=6 length 48 from 453fdb02 69.63.219.2
> receive: at 38 132.246.168.2<-69.63.219.2 restrict 00

> receive: at 182 132.246.168.2<-69.156.105.192 restrict 00
> receive: at 182 132.246.168.2<-69.156.105.192 mode 3 code 2
>  MCAST *****sendpkt(fd=6 dst=69.156.105.192, src=132.246.168.2, ttl=0,
> len=48)
> transmit: at 182 132.246.168.2->69.156.105.192 mode 4


> > Ray> I am running stratum-1 servers with NTP version 4.1.0.

Compare the above two client addresses in the output of
"ntpdc -nc monlist 132.246.168.2" :

remote address  port local address count m ver drop   last   first

69.63.219.2      353 132.246.168.2    99 3 3      0     18    6354

69.156.105.192  2605 132.246.168.2    11 3 4      0    294    6309


Then examine this piece of code in ntp-4.1.0/ntpd/ntp_proto.c receive() :

        if (!(SRCPORT(&rbufp->recv_srcadr) == NTP_PORT ||
            SRCPORT(&rbufp->recv_srcadr) >= IPPORT_RESERVED)) {
                sys_badlength++;
                return;                         /* invalid port */
        }

QED.  Time to upgrade to a later version ...

-- 
Ronan Flood <usenet at umbral.org.uk>




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