Firewall Wizards mailing list archives
Re: Acqusition of time
From: "Martin Peikert" <Martin.Peikert () discon de>
Date: Thu, 30 Jan 2003 10:23:00 +0100
Ben Nagy wrote:
If a firewall can't reach an NTP server because of some transient network condition the clock doesn't automatically go haywire - it will just start drifting as per the normal accuracy of the hardware clock, no?
Not necessarily. You could use clockspeed, see http://cr.yp.to/clockspeed.html
,----------------------------------------------------------------------- | clockspeed uses a hardware tick counter to compensate for a | persistently fast or slow system clock. Given a few time measurements | from a reliable source, it computes and then eliminates the clock | skew. `----------------------------------------------------------------------- and ,----------------------------------------------------------------------- | Typical success story: I started clockspeed on one of my Pentium | computers at home on 1998-05-05. I ran sntpclock (through a 28.8 | dialup line) once on 1998-05-05 and once on 1998-05-30. On 1998-08-22, | after no network time input for nearly three months, the clock was | just 0.21 seconds off. `-----------------------------------------------------------------------So, if a firewall can't reach an NTP server a longer time, I would think that you really have a problem ;-) But for a sufficient length of time clockspeed will do the job and keep the time from drifting too far...
GTi _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
Current thread:
- RE: Acqusition of time, (continued)
- RE: Acqusition of time Paul D. Robertson (Jan 29)
- RE: Acqusition of time dave (Jan 29)
- RE: Acqusition of time Tina Bird (Jan 29)
- Re: Acqusition of time Volker Tanger (Jan 29)
- Re: RE: Acqusition of time Brian Monkman (Jan 29)
- Re: RE: Acqusition of time Paul D. Robertson (Jan 29)
- Re: RE: Acqusition of time Joseph S D Yao (Jan 30)
- Re: Acqusition of time Volker Tanger (Jan 29)
- Re: RE: Acqusition of time Paul D. Robertson (Jan 29)
- Re: Acqusition of time Brian Ford (Jan 29)
- Re: Acqusition of time Ben Nagy (Jan 30)
- Re: Acqusition of time Martin Peikert (Jan 30)
- Re: Acqusition of time Frank Knobbe (Jan 31)
- Re: Acqusition of time Kevin Steves (Jan 31)
- Re: Acqusition of time Ben Nagy (Jan 30)
- Re: Acqusition of time Martin Peikert (Jan 31)