Renumber network & Keep IPs for DHCP clients

[Sysadmin]

I'm using 192.168.1.0 with mask 255.255.255.0. The 254
IPs my DHCP gives is not enough. I want delete DHCP scope
and recreate as 192.168.0.0 with mask 255.255.254.0
giving me 508 IPs i.e. 192.168.0.1 - 192.168.0.254 and
192.168.1.1 - 192.168.1.254 - Want to make this will work
right? Also I have about 30 printers with IPs assigned by
DHCP. How can I make sure that when I delete the
192.168.1.0/24 scope and create 192.168.0.0/23 scope, the
printers will maintain the same IPs so I don't have to
reconfigure printers for users, thanks.

 

[Phillip Windell]

I'm using 192.168.1.0 with mask 255.255.255.0. The 254
IPs my DHCP gives is not enough. I want delete DHCP scope
and recreate as 192.168.0.0 with mask 255.255.254.0
giving me 508 IPs i.e. 192.168.0.1 - 192.168.0.254 and
192.168.1.1 - 192.168.1.254 - Want to make this will work
right?

Why wouldn't it? Just do it,... that is the way it is supposed to be done.
The only thing that changes is the Address Range and the Mask.

Also I have about 30 printers with IPs assigned by
DHCP. How can I make sure that when I delete the
192.168.1.0/24 scope and create 192.168.0.0/23 scope, the
printers will maintain the same IPs so I don't have to

That is part of creating the scope properly. You must recreate any
Reservation or Exclusions that were in the old scope. The printers will be
reconfigured because a new mask is required even when the IP is still the
same.

The truth is when you get over 250 hosts you need to consider segmenting
your LAN with a LAN Router rather than making the single segment bigger.
Performance begins to degrade at that many hosts on the same segment.

 

[Sysadmin]

-----Original Message-----



Why wouldn't it? Just do it,... that is the way it is supposed to be done.
The only thing that changes is the Address Range and the Mask.

That is part of creating the scope properly. You must recreate any
Reservation or Exclusions that were in the old scope. The printers will be
reconfigured because a new mask is required even when the IP is still the
same.

The truth is when you get over 250 hosts you need to consider segmenting
your LAN with a LAN Router rather than making the single segment bigger.
Performance begins to degrade at that many hosts on the same segment.

I haven't actually segmented a network before. Can you
tell me how I will go about doing this.

 

[Phillip Windell]

I haven't actually segmented a network before. Can you
tell me how I will go about doing this.

Not if you don't already have some idea how to go about it. That's kind of
like asking to teach you how to build your own airplane in three easy steps
in a 100 words of less. Here's the best I can do.....

You need a router (a real router, not a SOHO internet-sharing-NAT box). You
need most likely another switch(s). Then cable it together with one segment
comming off each interface of the router. The simplest router would be an
old NT4.0 Workstation box with two NICs and IP Forwarding enabled. The
first segment would be your origninal 192.168.1.x (255.255.255.0) network
and the second segment could be for example 192.168.2.x (255.255.255.0).
This avoids any "splitting" with masks and the complexities and rules that
go along with it.

The router would not need an "static routes" nor would it need any "routing
protocols" active. It is just a simple two segment design with each segment
being classified as a "Directly Connected Network" from the router's
perspective. A router will automaitcally know what to do with a "Directly
Connected Network" so there are no "routes" to configure.

The Router would be the Default Gateway of *all* the other machines.

Whatever you use for the "Internet Sharing Device" will most likely (but not
always) be the Default Gateway of the Router. But the Router will *not* be
the DFG of the Sharing Device. The Internet Sharing Device will have a
Static Route configured on it that uses the Router as the "gateway" (not
default gateway) to reach the segment that is opposite the one the Internet
Sharing Device is part of. This Device's DFG will be the same as it already
is now.

I don't know if that is less than 100 words or not.