Re: Moving DHCP from Netware to FreeBSD

From: jpd (read_the_sig_at_do.not.spam.it)
Date: 08/30/04 

Date: Mon, 30 Aug 2004 21:15:28 +0000 (UTC)

On 2004-08-30, Rob MacGregor <rob_macgregor@hotmail.com> wrote:
> knob wrote:
>> Yeah... and how do I deal with all the currently leased
>> ip addresses?
>
> Practically speaking, that's non trivial. I'd suggest that what you do
> is drop the lease length to, say, an hour. Then at a quiet point (a
> weekend), prepare the new server, switch the lease on the old one to
> something really short (maybe 1 or 2 minutes). Give it an hour so that
> everybody is using a really short lease and switch servers. That way
> nobody should be affected, and any problem will be resolved quickly.

This is the ``obvious'' way I'd suggest, too. Move everything to an
awfully short lease time. Once everything has moved, kill the old server
and replace it. Most clients (those that care anyway) will ask for their
old IP and probably get it. (I think. isc-dhcpd-v3 will do so if it can
do based on previous occurences in the leases file. I don't know what it
does if a client asks for an ip the server has no prior record of. Check
this.) As long as the dhcpd-clients are not servers (those should be
bound to MAC or so anyway) there should be not much problem.

I don't consider killed irc bot connections and the like a problem.
YMMV, etc.

> However, the format of the lease file is simple enough, it has lots of
> entries like this:
[snip]
> If you can dump that data from the old server, you'd have a chance. Of
> course, while you're doing this, another address may be allocated...

The leases file is pretty well documented, I think the problem would
be much more in _extracting_ the data. But what do I know, no clue how
novell does this kind of thing. 

-- 
  j p d (at) d s b (dot) t u d e l f t (dot) n l .

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