Low cost way to "bridge" two networks using different ip addresses

Can anyone advise me of a low cost solution to bridge two networks operating on different ip address ranges, ie network 1 is operation in 192.168.11.xxx range and  network 2 is operating in 10.0.0.xxx range.

Specifically, I need to access the hard drive on a computer on the 10.0.0.xxx network as a mapped network drive from a computer on the 192.168.11.xxx network.

Thanks for any help

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This is my understanding of the current situation, please correct me if I am wrong:

There is one box using 10.0.0.x.
You have many boxes using 192.168.11.x
They are all connected using switches.
You need to map a windows share on the 10.0.0.x box from one or more 192.168.11.x boxes.
You have no way of changing the network configuration on the 10.0.0.x box.

The first option would be to set up one box to route between the networks (that is, one pc/router with IP addresses in both IP networks (for example and and configured to route between them). Then changing the routing on all the other boxes so that they go through this router when they try to access the other network (route add network netmask gw

The problem is, you would need to change the network configuration on the 10.0.0.x box to do this (you would have to tell it that it can reach 192.168.11.x through Since it seems that you can't, this potential solution looks like a no-go.

An alternate possibility is to configure the 192.168.11.x pcs that need access to the 10.0.0.x share so that they also have an IP address in the 10.0.0.x range. In Windows XP you can do this by going to the network connection properties, then Internet Protocol (TCP/IP) settings, click Advanced and then add a 10.0.0.x address/netmask
Crossing IP networks is called routing.  There are various inexpensive ways to do this, the cheapest being get a second NIC for a computer and connect it to both IP subnets and configure it to be a router (enaable IP forwarding).

However, this depends on the physical and logical  setup of the network

Any small workgroup router should work.   Disable any firewalling, set up the WAN side on 1 network, the LAN side on the other.
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EricIT ManagerCommented:
What is the senerio?
how is it currently all conected together?
single Default gateway device?
evanstestAuthor Commented:
The scenario is as follows:

The main network is on 192.168.11.xxx.  We have many items of equipment connected to that network via a number of unmanaged switches.

On the 10.0.0.xxx network we only have one device (a video streamer).  This device is essentially a computer but it has a fixed ip address of that we cannot change.

We put video files onto the streamer by just dumping them onto the streamer harddrive.  This is presented as a mapped network drive.

What we want to be able to achieve is to place and delete video files onto the streamer from any computer on the 192.168.11.xxx network.

We could assign a single PC with two NICs to be the physical connection between the video streamer and the 192.168.11.xxx network.  If we do this, how would we configure that PC (Windows xp) to forward packets between the two NICs?
How to enable IP forwarding in XP: http://support.microsoft.com/kb/315236

Once you do this, you need to setup routing tables in any computer that needs to get to the other subnet.

If you truly have all un-managed switches and no routers in your current enviroment you might be able to just configure two IP addresses on a single NIC.  One in each subnet.  You still need to enable IP forwarding and setup the route table, but you would not need to get a second NIC.
evanstestAuthor Commented:
Thanks for the pointer to ip forwarding in XP.

How do I go about setting up routing tables on the computers?

EricIT ManagerCommented:
Why dont you just give the streaming pc two IP addresses. you dont even need two nics.
Simply go in to advanced properties of the TCP/ip settings on it, and make the secondary IP a 192.168 subnet address and wallah.
am i missing something? seems like the easy solution.
EricIT ManagerCommented:
Incase that would not work, what is the physical layout?
what gateway does the 10.x use? or is it strictly private w/ no internet access etc?
i.e. is it a shared gateway, seperate gateway, no gateway?
evanstestAuthor Commented:
I can't access any TCP/IP network settings on the video streamer.

I believe the video streamer is running Linux but it has been packaged to not look like a PC, ie no keyboard or mouse or monitor connectors.  The only access we have to it is that its hard drive is set up to be "shared" and we can access it from a connected PC by mapping its drive.   ie on its harddrive there is a folder called "video".  The manufacturer of this product ships a utility that you run on another pc that maps \\\video\ to show as z:\ on the "client" PC.

The 10.0.0.xxx is just this single box - this video streamer. It has no gateway and no internet access.

As I said above, I need to be able to access the video streamer from any PC on the 192.168.11.xxx network.

I was thinking I need a "Box" with at least two NICs.  One NIC connects to the streamer and the second NIC connects to a switch connected to our 192.168.11.xxx network.  That "box" would need to provide some kind of bridging or routing between the 192.168.11.xxx network and the 10.0.0.xxx streamer.

From the earlier posts it seemed that an old win xp pc with two NICs could be pressed into service as this "box".
It sounds like they want to get to the 10. address from any/every computer in the 192. subnet.  In which case they need to:

    1) just change everything over to the 10. subnet.
    2) Give everything two IP addresses, one in the 192 and one in the 10
    3) Setup on PC as a router and add the needed route commands.

What is your default router?  It may just be simpler to add a route to it that points to the 10 subnet and point it to the 192 address of the PC that are you setting up as the router.  Example:  Say your current default route is and the IP address of the XP box that you are going to make your router is

On the default router you just add a route for (/24 is mask that points to  All PC will go to first, and it will redirect them to if they need to get to anything  in the subnet.
evanstestAuthor Commented:
Unfortunately options 1. and 2. are not open to me.  The main network has to stay at 192.168.11.xxx

I also don't have access to the main router.  I believe the "router" is a windows server 2003 box but I don't have access to it.

We are installing this video streamer onto a customer site as part of a larger "test system".   I need to really find some way to access the 10.0.0.xxx device that is transparent to the customer's existing network.

you pointed me before to an article on ip forwarding in windows xp and then said "Once you do this, you need to setup routing tables in any computer that needs to get to the other subnet".  I don't really know how to do this.  Is there anyway of setting up a single windows XP box that hangs off the network that will give all computers access to the 10.0.0.xxx device without needing to make changes to the individual PCs on 192.168.11.xxx?

Thanks for all comments.
The only way I can think of that MIGHT work is to setup a box that is in both subnets and install software that can do NAT and NAT the 10.0.0.x address to a 192.168.11.y address.  Have the customers setup their computer to communicate with the 192.168.11.y address.

This MAY work as some things do not work well with NAT.
evanstestAuthor Commented:
need to leave for evening now.  Will try out things tomorrow and feedback.  Thanks for all help so far.
EricIT ManagerCommented:
You could throw a cheap NAT device in the mis.  (linksys) etc.
Port forward the share.
Then on your default gateway make a static route to the linksys router.
so basically  a pc will be like i want 10.0.x.x, thats not my network send the request to the default gateway.  Default gateway will say, hey I know where that is and send it to the very specific IP address.
Same linksys device.   Set up the linksys to put the video heap in the DMZ zone forwarding all packets to it.
linksys =
clients try to connect to linksys.  linksys forwards all traffic to video heaps ip.
Maybe not the best. but sub 50 bucks is pretty cheap which is what you requested?
evanstestAuthor Commented:
can you give me a model number on the linksys?
EricIT ManagerCommented:
Do you ahve any available to test?  one from home?? spare ??
is only 40 bucks. but I have not done exactly what your asking.  I am almost positive it will work.  Can anyone validate or debunk my solution?
Were several comments here while I was typing mine above.

If no network changes can be done to the router, to the video streamer box or to the 192.168.11.x PCs, this becomes a bit harder.

ecszone, as far as I can tell a simple NAT router won't fix this. It will masquerade the box, making it look like it is on 192.168.11.x from the POV of the devices on 192.168.11.x. However the video streamer on has, as far as I understand, no gateway set. So when it receives traffic from 192.168.11.x it won't know how to send it back. One will need to do NAT both ways, making the video streamer appear as having a 192.168.11.x address from the pov of the 192.168.11.x PCs and making the 192.168.11.x PCs appear as being on 10.0.0.x from the POV of the video streamer. This is fairly unusual, and I have doubts that a cheap home-grade router can be configured that way. A cisco router or a Linux PC should be able to do it, but I don't have any configurations for this available right now.
EricIT ManagerCommented:
You might be right> I think i did something very similar. But i may have change the gw of the other box  i dont remember.
I figured it might work as long as they did not need to do the streaming through this router.
they are streaming now i assume already, so i thought maybe this would work.
You could very well be right. Figured if he had something laying around it was worth a shot
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