Re: Iptables "-m time" option doesn't update when the clock changes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 02/04/12 23:07, /dev/rob0 wrote:
On Mon, Apr 02, 2012 at 08:57:28PM +0100, Sebastian Arcus wrote:
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

Did you substitute the changed time? I don't see how using different
times in your rules would make no difference. Indeed, if not changing
times, reloading the same rules would make no difference.

Sorry - you are right - I didn't substitute the times in the firewall rules. On the other hand - a script which would restart the machine is easier (in this particular case) - than one which would amend the firewall rules and reload them.

I'm happy to run any other tests on Slackware if somebody can figure out what needs testing.
--
To unsubscribe from this list: send the line "unsubscribe netfilter" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Netfilter Development]     [Linux Kernel Networking Development]     [Netem]     [Berkeley Packet Filter]     [Linux Kernel Development]     [Advanced Routing & Traffice Control]     [Bugtraq]

  Powered by Linux