[ntpwg] [dhcwg] Re: Network Time Protocol (NTP) Optionsfor DHCPv6

[Mark Andrews]

> On Nov 25, 2007, at 3:24 PM, Brian Utterback wrote:
> > If a client is served an IP address at start up time, it has no  
> > choice but to use that address for the
> > entire time it is up and running.
> 
> This is simply not true.   The client would get the currently- 
> configured NTP server IP address every time it renews its lease.    
> It's true that some NTP clients may not bother to check their  
> configuration information for updates, but it is not true that they  
> have no choice - checking for configuration updates is trivial.
> 
> Indeed, I would say that at this late date, a network service that  
> gets its configuration information from the DHCP client, but does not  
> follow updates to that information, is broken.  Information provided  
> by the local DHCP server will most likely change when the client moves  
> from network to network.   The information that worked on one network  
> may not work at all on another.   This is true whether the information  
> is a domain name or an IP address.

I would think that this should be a push operation from the dhcp
client rather than a pull operation.  A trivial push would be for
the DHCP client to re-start the NTP client on address change (NTP
server and optionally lease address change).

I already do the later as the NTP client doesn't notice lease address
changes.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org