2 subnets on Windows XP Pro

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Redwind3303 - 24 Jan 2005 19:47 GMT

I am trying to connect to two subnets in Windows XP Pro, 10.x.x.x and
192.168.x.x. I have DHCP on the 192 subnet and have a static IP on the 10
side. I have two NIC's. One on the 192 side using DHCP and one on the 10
side set to the static IP needed. I have a terminal emulator that needs to
access the 10 side. The terminal emulator connection is intermittent. Is
there a way, in Windows XP Pro, to just forward the emulators request
directly to the 10 side NIC as it will take forever to connect or not connect
at all?

Once the 10 is connected, its access speed is great.
If I unplug the CAT or disable the NIC on the 192 the 10 side works.
I tried adding the DNS staticly to the 10 but this removed the 192 gateway.

Reply to this Message

Doug Sherman [MVP] - 24 Jan 2005 21:08 GMT

Yes, you can do this with XP Pro:

1. On the XP machine, enable routing:

Start/Run regedit ENTER

Navigate to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Double click on IPEnableRouter and set its value to 1.

2. On the XP machine configure a static IP for the 192.168.x.x NIC.

3. Any machine on the 192.168.x.x subnet seeking to reach a machine on the
10.x.x.x subnet must have one of the following:

The XP's 192.168.x.x address as a default gateway; or
A different default gateway which has a static route to the 10.x.x.x network
that points to the 192.168.x.x address of the XP machine; or its own static
route:

route add 10.0.0.0 mask 255.0.0.0 <exact IP address of XP's 192.168.x.x NIC>

4. Machines on the 10.x.x.x network must use the 10.x.x.x NIC on the XP
machine as a default gateway; or use a different gateway which has a static
route to the 192.168.x.x network pointing to the 10.x.x.x address of the XP
machine; or have their own static route:

route add 192.168.0.0 mask 255.255.0.0 <exact IP address of XP's 10.x.x.x
NIC>

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

> I am trying to connect to two subnets in Windows XP Pro, 10.x.x.x and
> 192.168.x.x. I have DHCP on the 192 subnet and have a static IP on the 10
[quoted text clipped - 8 lines]
> If I unplug the CAT or disable the NIC on the 192 the 10 side works.
> I tried adding the DNS staticly to the 10 but this removed the 192 gateway.

Reply to this Message

Vincent LaBonte - 25 Jan 2005 17:55 GMT

Thank you for the reply. Your suggestion still may work on a per PC scale as
it is a routing issue. I should clearify that I dont need a gateway. I have
two seperate routers already. I need three Win XP Pro machines on the
network to access the 192 router as well as the 10 router each with an
individual static IP address on the 10 side. The rest of the network doesnt
need to see the 10 side. The three XP PC's each have two NIC's in them.
One to access the 192 side, one to access the 10 side. The only device the
10 side NIC needs to get to is a leased server. The 192 side handles the
internal network. The XP Pro machines that are not part of the internal
domain will access the 10 server after a minute or two. The XP Pro machine
that is part of the internal domain will not access the 10 side at all even
though it accessed it when it was not on the domain.

I hope I have made my request a bit clearer. If I've muddled it , sorry.

Thank you,
Vincent LaBonte

> Yes, you can do this with XP Pro:
>
[quoted text clipped - 47 lines]
> > I tried adding the DNS staticly to the 10 but this removed the 192
> gateway.

Reply to this Message

Doug Sherman [MVP] - 25 Jan 2005 20:34 GMT

This sounds very different from what I thought you were trying to do. If
the only machines that need to access both networks are in fact connected to
both networks; then you don't need routing at all.

The gateway issue is different. If both routers are for Internet access,
then the best you can do is configure a preferred gateway - see:

http://support.microsoft.com/default.aspx?scid=kb;en-us;299540

If one or both routers are gateways to other subnets, then you will have to
configure static routes somewhere.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

> Thank you for the reply. Your suggestion still may work on a per PC scale as
> it is a routing issue. I should clearify that I dont need a gateway. I have
[quoted text clipped - 65 lines]
> > > I tried adding the DNS staticly to the 10 but this removed the 192
> > gateway.

Reply to this Message

Vincent LaBonte - 25 Jan 2005 21:51 GMT

The machines are connected to both networks. My issue is that the Terminal
emulator either takes forever to connect to the 10 server or does not connect
at all. Only the 192 accesses the internet but the 10 still needs a gateway
as the clients are 10.1.x.x and the server is 10.2.x.x with a class B subnet
mask (255.255.0.0 or /16). So... If I direct the PC threw the XP routing to
send 10 network requests to the 10 NIC and everything else to the 192 then we
should be ok. Does this sound correct?

Again, thanks for the assistance,
Vincent LaBonte

> This sounds very different from what I thought you were trying to do. If
> the only machines that need to access both networks are in fact connected to
[quoted text clipped - 97 lines]
> > > > I tried adding the DNS staticly to the 10 but this removed the 192
> > > gateway.

Reply to this Message

Doug Sherman [MVP] - 26 Jan 2005 20:49 GMT

Well, originally you described the network as 10.x.x.x - which implies a
subnet mask of 255.0.0.0. If instead the mask is 255.255.0.0, then the
10.2.x.x server is not on the same subnet as the 10.1.x.x machines. This
could well be the cause of your communication issues - OR - Is this what the
router on the 10.1.x.x network is for? ie. 10.1.x.x connects to 10.2.x.x
through a router? So you have 3 subnets - not 2? If so, you need to
configure a static route on the multihomed machines:

route add 10.2.0.0 mask 255.255.0.0. <IP address of gateway to 10.2.x.x
network>

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

> The machines are connected to both networks. My issue is that the Terminal
> emulator either takes forever to connect to the 10 server or does not connect
[quoted text clipped - 53 lines]
> > > >
> > > > Navigate to

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

> > > > Double click on IPEnableRouter and set its value to 1.
> > > >
[quoted text clipped - 49 lines]
> > > > > I tried adding the DNS staticly to the 10 but this removed the 192
> > > > gateway.

Reply to this Message

Vincent LaBonte - 27 Jan 2005 06:17 GMT

Hi Doug,

Thank you for the help. Even though I called Microsoft today and got it
worked out before I read this, "Is this what the router on the 10.1.x.x
network is for? ie. 10.1.x.x connects to 10.2.x.x through a router? So you
have 3 subnets - not 2? If so, you need to configure a static route on the
multihomed machines:" hit it on the head. The route add command is what I
ended up with. It works flawlessly now. Interesting point on the subnets.
I never considered the 10.2.x.x since it is off sight. And yes, 10.x.x.x
implies a (and is a) class A network but what I am working with is subnetted.
Sorry for the confusion there. It ends up I cannot have two gateways on one
machine and that was the issue.

Again, thank you for the help,
Vincent LaBonte

> Well, originally you described the network as 10.x.x.x - which implies a
> subnet mask of 255.0.0.0. If instead the mask is 255.255.0.0, then the
[quoted text clipped - 153 lines]
> > > > > > I tried adding the DNS staticly to the 10 but this removed the 192
> > > > > gateway.

Reply to this Message

Doug Sherman [MVP] - 31 Jan 2005 21:02 GMT

I hear you - you only built or manage 2 subnets, so it makes perfect sense
to describe the scenario as only involving 2 subnets. They say that English
is the most precise language, but they also say a picture is worth a 1000
words. We need to develop a canned network diagram that can be edited and
pasted into posts on this newsgroup. I'll see what I can do.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

> Hi Doug,
>
[quoted text clipped - 169 lines]
> > > > > > > I tried adding the DNS staticly to the 10 but this removed the 192
> > > > > > gateway.

Reply to this Message

Robert L [MS-MVP] - 24 Jan 2005 21:47 GMT

sounds like routing issue. posting the routing table here may help. to do
that, use route print command.

Signature

For more and other information, go to http://howtonetworking.com and
http://ChicagoTech.net

Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, Remote Access on
http://www.HowToNetworking.com
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net

>I am trying to connect to two subnets in Windows XP Pro, 10.x.x.x and
> 192.168.x.x. I have DHCP on the 192 subnet and have a static IP on the
[quoted text clipped - 13 lines]
> I tried adding the DNS staticly to the 10 but this removed the 192
> gateway.

Reply to this Message