Re: [dhcwg] Review of draft-ietf-dhc-dhcpv6-failover-protocol-00

[Brian Haberman <[e-mail]>]

As the AD who shepherds the time-related WGs...

On 11/30/15 11:56 AM, Simon Hobson wrote:
> Kim Kinnear <[e-mail]> wrote:
> 
>> Folks,
>> 
>> One of Bernie's comments on the failover draft was:
>> 
>>> -          7.1 (Time Skew) – Should we require NTP to synchronize
>>> the clocks on failover partners?
>> 
>> The current draft (-00.txt) has a capability to allow the failover 
>> protocol to operate with two machines which have clock skew of a 
>> largely arbitrary amount (limited in some way to perhaps 24 hours
>> or something).  So two systems that are 3-5 minutes apart (the
>> usual skew, if any) will work fine.
>> 
>> Bernie is suggesting that we require failover partners to have 
>> essentially synchronized time by requiring NTP sync.  If they are 
>> synchronized to the level of 1-2 seconds, that would be
>> synchronized for the purposes of this protocol.  We aren't talking
>> milliseconds here.
> 
> I see two points :
> 
> 1) If the time should be synced, then I would suggest merely
> requiring that, rather than specifying NTP - ie specify the what
> rather than the how.

The above makes sense since NTP is not the only protocol available to
synchronize time.

Regards,
Brian