Guys,

I know you cannot route 10.x.x.x address over the
internet. But does anyone one if that address range can
be routed internally within a LAN. i.e can Machine A (ip
addr (10.x.x.x) communicate with machine B on ANOTHER
subnet on the same LAN.

Yep, but you need a router. IP is a fully-routable protocol.

--
Richard G. Harper [MVP Win9x] (E-Mail Removed)
* PLEASE post all messages and replies in the newsgroups
* for the benefit of all. Private mail is usually not replied to.
* My website, such as it is ... http://rgharper.mvps.org/
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"Mark" <(E-Mail Removed)> wrote in message
news:19a501c49c33$62adf7d0$(E-Mail Removed)...
> Guys,
>
> I know you cannot route 10.x.x.x address over the
> internet. But does anyone one if that address range can
> be routed internally within a LAN. i.e can Machine A (ip
> addr (10.x.x.x) communicate with machine B on ANOTHER
> subnet on the same LAN.

These are the IANA private "black hole" networks
defined in RFC 1918:

10.*.*.* / 8
172.16-31.*.* / 12
192.168.*.* / 16

These address ranges are excluded from routing on
the public Internet simply by the way the routers and
routing protocols are configured to block them in
compliance with the RFC and IANAs requirements.

But otherwise they are as good as any other IP addresses
for use on your own private network. Better, in fact, since
you know you won't be mapping out any real, public
address ranges by using them.

Steve Duff, MCSE, MVP
Ergodic Systems, Inc.

"Mark" <(E-Mail Removed)> wrote in message news:19a501c49c33$62adf7d0$(E-Mail Removed)...
> Guys,
>
> I know you cannot route 10.x.x.x address over the
> internet. But does anyone one if that address range can
> be routed internally within a LAN. i.e can Machine A (ip
> addr (10.x.x.x) communicate with machine B on ANOTHER
> subnet on the same LAN.

On Thu, 16 Sep 2004 14:23:18 -0700, "Mark"
<(E-Mail Removed)> wrote:

>I know you cannot route 10.x.x.x address over the
>internet. But does anyone one if that address range can
>be routed internally within a LAN. i.e can Machine A (ip
>addr (10.x.x.x) communicate with machine B on ANOTHER
>subnet on the same LAN.

Sure. But you do need to have separate logical networks of course.
If you use a 255.0.0.0 netmask, these addresses will never route since
every system knows they don't need to. But you could route a 10.0.1.x
with a mask of 255.255.255.0 to a 10.0.2.x address with the same
netmask. Provided you have a router of course.

Jeff

"Jeff Cochran" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Thu, 16 Sep 2004 14:23:18 -0700, "Mark"
> <(E-Mail Removed)> wrote:
>
>>I know you cannot route 10.x.x.x address over the
>>internet. But does anyone one if that address range can
>>be routed internally within a LAN. i.e can Machine A (ip
>>addr (10.x.x.x) communicate with machine B on ANOTHER
>>subnet on the same LAN.
>
> Sure. But you do need to have separate logical networks of course.
> If you use a 255.0.0.0 netmask, these addresses will never route since
> every system knows they don't need to. But you could route a 10.0.1.x
> with a mask of 255.255.255.0 to a 10.0.2.x address with the same
> netmask. Provided you have a router of course.
>
> Jeff

Or a windows PC running Routing and Remote Access. Standard on Server OS.
Can be added free to 2k pro/NT4 etc.

"Paul Landregan" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Or a windows PC running Routing and Remote Access. Standard on Server OS.
> Can be added free to 2k pro/NT4 etc.

NT4.0 (both Server and WKSTN) would function as a router without RRAS. Even
2000 can, but is less configurable. I'm not sure about 2003.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com