Re: REMINDER: LEAP SECOND

[Mel Beckman <mel () beckman org>]

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