Sign in with
Sign up | Sign in
Your question

LAN IP Scheme Change

Last response: in Windows 2000/NT
Share
May 11, 2005 10:03:43 AM

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

Our company has 15 servers and about 150 PC's. When I arrived, a
192.168.1.x/24 IP scheme was being used, and management did not want it
changed. Now we are running out of IP's. We are looking to move to a
192.168.x.y/16 IP scheme. I know that in my experience, most small
networks seem to use the 192.168.1.x/24 IP scheme, but when I look at
any TCP/IP guide, it shows the 192.168.x.y/16 as one of the 3 private
IP blocks. Is the 192.168.1.x/24 also private? Why aren't people
using the 192.168.x.y/16? I'm wondering if there is something I'm not
seeing about this scheme that will cause problems, in which case I'll
just move to a 10.x.y.z/8 scheme.

Also, in regards to the 192.168.x.y/16 scheme, as long as everyone has
the same subnet mask (255.255.0.0), will a computer with say a
192.168.0.50 IP be able to communicate with a server that has an IP of
192.168.10.100, and vice versa? I believe they would, but I'm worried
that it's not that simple. As you can see my TCP/IP skills are a bit
rusty. It's been a while since I've gotten involved with this.

Thanks in advance for the help!

Tony

More about : lan scheme change

May 11, 2005 4:00:43 PM

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

Thanks a lot Patrick.

The reason we are running out of IP's is
a) We have about 30 jet directs on the network and that keeps growing,
and
b) Our engineering department is creating new PC boards that will all
need their own IP. Moving forward, the amount of these devices could
grow to be very large.

I do like the idea of setting up subnets for the different departments
in our company. Is there a good number to go by when deciding on the
maximum amount of devices that should be in a subnet?

Tony
Anonymous
May 11, 2005 5:41:37 PM

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

In article <1115816623.794308.12910@g43g2000cwa.googlegroups.com>,
Tony <TAlbergo@naii.com> wrote:
>Our company has 15 servers and about 150 PC's. When I arrived, a
>192.168.1.x/24 IP scheme was being used, and management did not want it
>changed. Now we are running out of IP's.

With 15 servers and 150 PCs, that's only 165 addresses out of about 254.
Are you looking to add 90 computers or devices to your network in the
near future? That's a pretty big jump.

Even so, there's nothing wrong with planning for the future...

>We are looking to move to a
>192.168.x.y/16 IP scheme. I know that in my experience, most small
>networks seem to use the 192.168.1.x/24 IP scheme, but when I look at
>any TCP/IP guide, it shows the 192.168.x.y/16 as one of the 3 private
>IP blocks. Is the 192.168.1.x/24 also private?

The 192.168.1.x/24 is just a subset of 192.168.x.y/16 network, so the
answer is YES, it's still private. The number after the '/' indicates
how many bits of the address do not change in the network. When you
see 192.168.x.y/16, it means that any address that starts with 192.168
will be in the range covered by that specification. Certainly, 192.168.1.x
will be in the larger range.

>Why aren't people
>using the 192.168.x.y/16? I'm wondering if there is something I'm not
>seeing about this scheme that will cause problems, in which case I'll
>just move to a 10.x.y.z/8 scheme.

What alot of people will do is create their own private networks like
192.168.1.x/24, 192.168.2.x/24, 192.168.3.x/24, etc. If you have logical
divisions in your company that can be easily seperated by routers (maybe
they're on their own switches right now), you can assign each area it's
own 192.168.x address and have your main router route between the several
private subnets.

>Also, in regards to the 192.168.x.y/16 scheme, as long as everyone has
>the same subnet mask (255.255.0.0), will a computer with say a
>192.168.0.50 IP be able to communicate with a server that has an IP of
>192.168.10.100, and vice versa?

You could do that also (just make your 192.168 network larger), but now
might be the time to create real subnets so as your company grows, you
won't try to put too many computers/devices on the same subnet (not usually
a good idea).

>I believe they would, but I'm worried that it's not that simple.

It's almost that simple.

>As you can see my TCP/IP skills are a bit
>rusty. It's been a while since I've gotten involved with this.

I think you've got most of the picture. Realizing that you could have
several private (sub)networks in the 192.168 address range is something I
would suggest you look into a little more before making a final decision.

Patrick
========= For LAN/WAN Protocol Analysis, check out PacketView Pro! =========
Patrick Klos Email: patrick@klos.com
Klos Technologies, Inc. Web: http://www.klos.com/
==== I don't think infinity is as big as it seems - P.Klos, 20-Mar-2005 ====
Related resources
Anonymous
May 11, 2005 6:47:39 PM

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

The Internet Assigned Numbers Authority (IANA) has reserved the following
three blocks of the IP address space for private internets:

10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

Because 192.168/16 is private, 192.168/17, 192.168/18 etc will also be
private. So yes 192.168/24 is private.

Most SoHo network equipment comes preconfigured to use 192.168/24 because
this will cater for 253 hosts (PCs) which is more than enough for these type
of environments.

If you were to use 10/8 thats a lot of hosts to have on a single subnet, a
more common practice would be to use 10/16 or even 10/24 and use routers to
interconnect the subnets.

With a 192.168/16 scheme, 192.168.0.50 and 192.168.10.100 would be on the
same LAN - the subnet mask for /16 is 255.255.0.0; so 192.168 is the network
portion of the address and anything after is host addressing.





"Tony" <TAlbergo@naii.com> wrote in message
news:1115816623.794308.12910@g43g2000cwa.googlegroups.com...
> Our company has 15 servers and about 150 PC's. When I arrived, a
> 192.168.1.x/24 IP scheme was being used, and management did not want it
> changed. Now we are running out of IP's. We are looking to move to a
> 192.168.x.y/16 IP scheme. I know that in my experience, most small
> networks seem to use the 192.168.1.x/24 IP scheme, but when I look at
> any TCP/IP guide, it shows the 192.168.x.y/16 as one of the 3 private
> IP blocks. Is the 192.168.1.x/24 also private? Why aren't people
> using the 192.168.x.y/16? I'm wondering if there is something I'm not
> seeing about this scheme that will cause problems, in which case I'll
> just move to a 10.x.y.z/8 scheme.
>
> Also, in regards to the 192.168.x.y/16 scheme, as long as everyone has
> the same subnet mask (255.255.0.0), will a computer with say a
> 192.168.0.50 IP be able to communicate with a server that has an IP of
> 192.168.10.100, and vice versa? I believe they would, but I'm worried
> that it's not that simple. As you can see my TCP/IP skills are a bit
> rusty. It's been a while since I've gotten involved with this.
>
> Thanks in advance for the help!
>
> Tony
>
June 14, 2005 6:28:06 PM

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

I like the subnet Idea in this senerio, as of right now you are either
switched or flat, if your switched you can get some control over the network
trafic and quiet down the subnets, however the broadcasts will kill you,. if
you subnet and moved to reasonably priced routers you can get layer 3
filtering and hold your broadcast traphic to a minimum, again I don't know
what these engineerring devices are may wanna subnet them off by self so they
don't tear up the network bandwidth


"Tony" wrote:

> Thanks a lot Patrick.
>
> The reason we are running out of IP's is
> a) We have about 30 jet directs on the network and that keeps growing,
> and
> b) Our engineering department is creating new PC boards that will all
> need their own IP. Moving forward, the amount of these devices could
> grow to be very large.
>
> I do like the idea of setting up subnets for the different departments
> in our company. Is there a good number to go by when deciding on the
> maximum amount of devices that should be in a subnet?
>
> Tony
>
>
!