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

[Kim Kinnear <[e-mail]>]

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.

Is that a good idea?  Should that be a requirement for DHCPv6
failover?

Most folks running our particular v4 failover seem to run synchronized
systems, though we have a few customers that don't.  Those systems
don't tend to be off by more than a couple of minutes, usually.

I'm interested in opinions as to whether we should require time sync
between failover partners for the DHCPv6 failover protocol.

Thanks -- Kim