[TriLUG] Windows DHCP to ISC DHCP migration
Joseph Mack NA3T
jmack at wm7d.net
Wed Oct 24 18:00:08 EDT 2007
On Wed, 24 Oct 2007, Shawn Hood wrote:
> 3) Shorten the lease time to a very small number, wait for all workstations
> to cycle. Shut off the Windows DHCP and startup Linux.
I'm with Chris.
You don't get a lot of choice with lease time. Windows
machines only ask for 5mins, even if you allow a longer
lease time. Linux machines ask for an hour. I suspect a
windows dhcpd will only grant a 5 min lease. So the
changeover has to occur in a time less than
However dhcpds don't tread on each other's toes. If you have
two of them running, when the client asks for an IP, it will
only accept a reply from one machine. The dhcpd will not
grant a lease for an IP which it thinks is free (from its
leases file) if there is a machine with that IP on the
network. (I think) you only need to two dhcpds to cooperate
if you've coupled the dhcpd to DNS.
So test your linux dhcpd machine off-line, then plug it into
the network of interest and then bring down the windows
dhcpd. The clients shouldn't know that the dhcpd server has
(I haven't done this - this is just my best guess)
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
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