[ntp:hackers] Configuration addition for ntpd

Heiko Gerstung heiko.gerstung at meinberg.de
Tue Jan 30 00:27:00 PST 2007

Hi Guys,

are there any news on the configuration file rewrite available? There 
are a couple of feature requests I saw in the past or maybe it is only 
me who would like to see them and I wonder if there are any of those 
points already handled in the new configuration file format/parsing.

It could be possible that one or the other of those points is already 
dealt with in the current codebase, I would appreciate any pointers in 
that direction.

1. apply "working" default restrict rules to hosts that are defined as 
ntp servers or peers in the config file

That means, if I have a line like this in my config file ...
server my.favourite.ntp.host
... ntpd would automatically apply restrict rules to it which simply 
allow me to accept time from it. If it is configured as a peer, it 
should per default be accepted as a peer.

Of course it should be possible to add a restrict line for that server 
in order to override the default restrict statements.

2. add a "dynamic" option to the server/peer config statement

This would tell ntpd to re-use the IP address it resolved for this 
hostname and do not try to resolve it again. An exemption to this rule 
should be that if the server does not respond at this IP to a couple of 
requests (i.e. for 4 queries in a row), ntpd should try to resolve the 
IP again and select another one, if available.

These two changes would help us getting rid of the problem with setting 
restrictions for pool servers or other servers with multiple (maybe 
round-robin based) DNS entries. The "dynamic" statement could also be 
used to solve the problem of ntpd running on a server 24/7 for 12 months 
and trying to request time from a dead pool server that did not respond 
for the last 3 months.

I am looking forward to your comments :-)

Best Regards,


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