First off, I want to give a big Thank You to Brad Doster and D. SKye Hodges. I am pretty sure that I have already figured out the answer
my questions because of the info you all provided. I need to double
check that what I understand is correct, though. ;-)

I have a WAN link that connects to a remote network, with a
/24 address scheme. I get to swap out the WAN link with a (wireless)

LAN link - but that will put the remote network on the same segment as

an existing network. Obviously, this means re-addressing all the
on the remote network.

The existing network is /24 - and already pretty full.

One other wrinkle is that both networks' DHCP subnets are configured
only hand out addresses in the x.x.x.50 - x.x.x.250 range. We have
machines that need static IP addresses, so we put manual IP addresses
the DHCP server, to hand out static addresses below 50.

Because adding the machines from the remote network would fill the
dynamic DHCP address range, we want to change the existing subnet mask

from /24 to /23 (from to

The plan is to export the remote network subnet in the DHCP management

console, and then search and replace the 172.16.230. data with
172.19.22. data - then import the subnet back in.

First question: will that work?

What we want to end up with is two ranges of dynamic IP address
assignments, and two ranges of static IP address assignments, all
one network segment. The 'lower half' of the range will be the
network, essentially untouched (except for the change in the subnet
mask). The 'upper half' of the range will be the statically addressed

machines from the remote network, and any overflow from the dynamic
address range in the 'lower half'.

Second question: is IP Subnet Pooling the proper way to hand out the dynamic addresses for the two blocks? Specifically, if I define two DHCP subnets, - .250 and - .250, and pool
two blocks together, does the DHCP server automatically start
addresses from the 172.19.22.x block when the 172.19.21.x block fills


Thank you in advance for any assistance you can give me.
David Gerisch