nanog mailing list archives
Re: REMINDER: LEAP SECOND
From: Mel Beckman <mel () beckman org>
Date: Sat, 20 Jun 2015 01:42:48 +0000
Harlan, This is cisco's recommended workaround, the ultimate conclusion of an exhaustive study of all Cisco firmware and after detailed post mortem analysis of two previous Leap seconds: https://tools.cisco.com/bugsearch/bug/CSCut33302 GSS Leap second update CSCut33302 Description Symptom: There are periodic leap second events which can add or delete a second to global time. When the leap second update occurs the GSS might hang and have to be reload or the kernel could crash and the GSS would reboot. Conditions: The leap second update will be propagated via Network Time Protocol (NTP) or via manually setting the clock. Workaround: Workaround, Turn off NTP prior to leap second and turn it back on afterward. Further Problem Description: None Or, in the immortal words of The IT Crowd: "Turn it off and on again!" If you run non-IOS server software of such fragility that it can't tolerate time slewing, just shut it down and power back up after The Leap. That's what your competitors are doing :) -mel beckman On Jun 19, 2015, at 4:15 PM, Harlan Stenn <stenn () ntp org<mailto:stenn () ntp org>> wrote: Baldur Norddahl writes: On 19 June 2015 at 23:58, Harlan Stenn <stenn () ntp org<mailto:stenn () ntp org>> wrote: Bad idea. When restarting ntpd your clocks will likely be off by a second, which will cause a backward step, which will force the problem you claim to be avoiding. If you are afraid that your routers will crash due to the leapsecond, then it would help to disable the thing that you think will crash them. Even if the router crashes when you enable it later on. Because then you can have one router crash at a time and have it happen in a service window where you are ready for it. Instead of having all routers in your whole network crash at exactly the same time. That' seems fair, as long as you turn off the time stuff only on your routers, and I'm assuming this is on routers that don't have supported software. H
Current thread:
- Re: REMINDER: LEAP SECOND, (continued)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 22)
- Re: REMINDER: LEAP SECOND shawn wilson (Jun 20)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 20)
- Re: REMINDER: LEAP SECOND shawn wilson (Jun 20)
- Re: REMINDER: LEAP SECOND Måns Nilsson (Jun 19)
- Re: REMINDER: LEAP SECOND Mel Beckman (Jun 19)
- Re: REMINDER: LEAP SECOND Majdi S. Abbas (Jun 19)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 19)
- Re: REMINDER: LEAP SECOND Baldur Norddahl (Jun 19)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 19)
- Re: REMINDER: LEAP SECOND Mel Beckman (Jun 19)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 20)
- Re: REMINDER: LEAP SECOND Mel Beckman (Jun 19)
- Re: REMINDER: LEAP SECOND Doug Barton (Jun 22)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 22)
- Re: REMINDER: LEAP SECOND Mel Beckman (Jun 23)
- Re: REMINDER: LEAP SECOND Harlan Stenn (Jun 23)
- Re: REMINDER: LEAP SECOND Mel Beckman (Jun 23)
- Re: REMINDER: LEAP SECOND Nick Hilliard (Jun 23)
- Re: REMINDER: LEAP SECOND shawn wilson (Jun 23)
- Re: REMINDER: LEAP SECOND Jared Mauch (Jun 23)
- Re: REMINDER: LEAP SECOND Nick Hilliard (Jun 23)