[ntp:questions] Question on "calldelay"

Danny Mayer mayer at ntp.isc.org
Sun May 6 19:43:28 UTC 2007

Harlan Stenn wrote:
>>>> In article <cv6rg4-68s.ln1 at klein-habertwedt.de>, Uwe Klein <uwe_klein_habertwedt at t-online.de> writes:
> Uwe> Hi, I have tried using calldelay 15 server $myserver burst prefer
> Uwe> .........
> I gotta wonder if 'burst' is really needed.

It's probably not wise since if the connection is not up and ready, then
you are just wasting the packets you send.

> I was initially wondering if $myserver was an IP or a name, but...
> Uwe> to (pre)start up my notorious ISDN dialup connection.  i have problems
> Uwe> with that.
> Uwe> in my (tcpdump) logs i can see
> Uwe> 	the initial ntpv4 client packet
> this implies you are able to turn the situation into an IP.

I suspect that the real problem is that the box is getting an IP address
assigned by DHCP and you need to rebind the local address first so that
the packet can go out from a valid address.

> Uwe> the syslog info from the ciscobox
> Uwe> that indicates the dialup being connected and then nothing.  the
> Uwe> initial packet seems to be dropped ( bahh, world loss )
> Uwe> 	dialup is taken down after timeout ( ~75 seconds )

Did NTP rebind the local address first?

> Uwe> if the connection is already up the initial ntpv4 client packet answer
> Uwe> from server delay 15 seconds 3 pairs of query answer packets.
> Uwe> My question: is the current poll aborted when the first packet is not
> Uwe> answered?

The protocol doesn't care. This is UDP. If it doesn't get a response it
will try again later. When later is depends on the stage that it's at.


More information about the questions mailing list