Re: Iptables "-m time" option doesn't update when the clock changes
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On 29/03/12 14:45, /dev/rob0 wrote:
On Thu, Mar 29, 2012 at 11:21:55AM +0100, Sebastian Arcus wrote:On 29/03/12 11:00, Jan Engelhardt wrote: </snip>The caveat with the kernel timezone is that Linux distributions may ignore to set the kernel timezone, and instead only set the system time. Even if a particular distribution does set the timezone at boot, it is usually does not keep the kernel timezone offset - which is what changes on DST - up to date. ntpd will not touch the kernel timezone, so running it will not resolve the issue. As such, one may encounter a timezone that is always +0000, or one that is wrong half of the time of the year. As such, using --kerneltz is highly discouraged.Thanks for taking the time to give a detailed reply. Just to make sure I understand correctly - would this mean that there is no reliable way to run time based iptables rules and have them keep up with DST changes correctly and automatically - without restarting the machine when the DST kicks in or out?Restarting the machine? Blasphemy! Why not simply reload the firewall rules? A simple at(1) job on the DST-to-standard and standard-to-DST dates to reload the rules, either using your distro's firewall management tools, or pipe iptables-save to iptables-restore (substituting for the changed times), ought to do the job just fine.
Thanks for the suggestion. However, restarting the firewall (which flushes and re-writes the rules) makes absolutely no difference. I have to actually restart the machine for the rules to behave according to the correct time. Maybe there is something wrong with the way Slackware updates the kernel TZ - as per Jan's post. I've posted to the Slackware list on linuxquestions.org to see if anybody knows more.
SebastianPS I agree with your position on restarting servers :-) but I don't seem to get any choice in this matter
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