Re: Running out of DHCP address leases howto rectify?

In news:3ff2a6af-9084-491c-ba84-1e84e387f2a5@xxxxxxxxxxxxxxxxxxxxxxxxxxxx,
connor_a@xxxxxxxxxxx <connor_a@xxxxxxxxxxx> typed:


Hi Ace,

Thanks for the reply and ideas. I have a single DC in the building
which also hosts DNS and DHCP for 4 floors.

We have about 20 DHCP leases available on the existing 147.109.x.y
subnet
This subnet needs to be migrated to a 10.16.128.0/23 subnet range
(10.16.128.0 - 10.16.131.0) so more hosts can be available.

What would be the best DHCP migration strategy to achieve this?

Thanks.

Sorry for the late reply.

So you are looking at a major IP migration from a public range to a private
range and not simply extending the current scopes. You have a major
undertaking on your hands. Let's see... from memory:

Come up with a plan that includes an IP range for all servers and static set
hosts, as well as an IP range for each floor, unless you simply use the same
subnet for teh whole building, which is what most designs entail, and MUCH
easier to deal with.
For the whole building, I would probably use, which will give you 65,000
IPs:
10.10.0.0/16

If you want to keep with the separate subnets for each floor, which I think
complicates matters with DHCP and connecitivity), I would break it down to
the following whch will give you 4096 hosts for each subnet:
10.10.0.0/20 (10.10.0.0 - 10.10.15.255)
10.10.16.0/20 (10.10.16.0 - 10.10.31.255)
10.10.32.0/20 (10.10.32.0 - 10.10.47.255)
10.10.48.0/20 (10.10.48.0 - 10.10.63.255)
etc

Change the DC/DNS servers IPs
Re-register them in DNS
Make sure all old IP refefences are manually removed if the registration
process above does not overwrite the old ones, which it should.
Create a new reverse zone for the planned IP subnets, Make sure updates are
allowed.
Change all of your servers' IPs.
Change any static hosts, including printer cards, and other IP static
entries.
Make sure the above works, AD is functional, the DCs and servers can get to
the printers, etc.
Make sure the router can handle NAT. If not, time to look for a new one.
Change the internal IP of the router.
If using multiple floors, change the static route entries on the edge router
to be able to get to the other subnets.
Test internet connectivity from your DCs and servers.
DHCP - Take note of exclusions, reservations, etc. Delete all scopes.
Create a new big scope, or multiples if you still dealing with separate
scopes for each floor.
Test with a couple of workstations, logons, internet connectivity, printers,
resource access, etc.

I'm sure I missed a few steps and only briefed over many. This should give
you a good start.

Ace


.

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