Communicating Between 2 Computers

[tray0011]

Hi Guys,

I have 2 winxp computers with seperate network addressing schemes (for simplicity purposes i'll leave out why i need it that way). How can i get the 2 computers (and any other computers in their network) to communicate totally as if they were on the same network. (do i need to create static routes - if so how).

computer A and computer B are connected to the router.

COMPUTER A
10.231.1.127
255.255.0.0
10.231.0.4
Linksys router (BEFSR81)
10.0.0.1
255.255.255.0

COMPUTER B
10.0.0.6
255.255.255.0
10.0.0.1

Your help would be greatly appreciated.
thanks,
Tray

 

[mlconley]

Yikes! I would be surpised if computer a can see the router at all, considering it is on a completly different subnet. The easiest way would be to set a second IP address and multihome computer a.

In order to set a static route, you need a routing device that will accomodate static routes. This is possible to do on a single interface, as well as a dual interface routing device (I use the term "routing device" becuase it needn't be a dedicated router.) I don't believe the linksys router will support static routes or multiple subnets per interface.

 

[tray0011]

If if i set the linksys router and computer B with 255.255.0.0 will it work without multihoming?

Can you explain your last comment - i don't think i understood it, because in the linksys router there is a page for setting static routes (though i'm not 100% familiar how that would be used in my scenario - would i need a second router for that?).

 

[wasisnt]

How about setting up a network bridge? XP supports software bridges.

http://www.homenethelp.com/web/howto/windows-xp-bridge.asp

MCSE NT 4.0, A+ & Network +

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[tray0011]

wasisnt

Thats a nice idea but i would prefer doing this via a router if possible.

Please respond with any other ideas - preferablly accomplishing this with the linksys - unless it's not possible.

what other network device would allow me to accomplish my goal?

Thanks guys

 

[mlconley]

If if i set the linksys router and computer B with 255.255.0.0 will it work without multihoming?

No, your netmask would have to be 255.0.0.0 becuase _only_ the first octets share a common value. using 255.255.0.0 means your network address changes from 10.0.0 to 10.0. Removing the second octet would set your netwok number at 10, the remaining octets are now host addresses on the "10" network

In order to route between different network ranges, in your case, 10.0.0.x and 10.231.x.x, plus your external IP address, the router needs an interface, physical or logical, in each subnet. Think of it this way: You can't get from interstate 93 to interstate 90 unless there is an exit somewhere on I93.

I suspect the static routes in the LinkSys are intened to route across the interfaces (i.e. lan to wan)

another thought: You might be able to use the internet sharing feature in windows XP if using a one-octet network is not an option.

In the same way that your linksys proxies one public address into several private addresses, internet sharing can proxy one private address on one network range into several private addresses in a separate address range.

 

[Davetoo]

What device do you have at 10.231.0.4? The key is you need to get that device and your Linksys router communcating, and build a route between them. The computers on either side don't really matter as long as the two devices they're connected to can communcate freely. Once that's done, you can build the routes between the two networks.

I'm Certifiable, not cert-ified.
It just means my answers are from experience, not a book.

 

[mlconley]

Lander215 raises a good point 10.231.0.4 is the exit for all things not 10.231. In other words to get to anything on the internet, or anything on the 10.0 network, all traffic will be directed to 10.231.0.4.

 

[tray0011]

Guys

10.231.0.4 is the main internet gateway (firewall).

(Lets' put aside getting out to the internet for a moment since i'm mainly concerned with communications between the 2 comps).

Tell me if the following changes your suggestion: The 10.231.0.4 firewall is not between the 2 networks, it only allows 'computer A' to get out to the internet. The Router and computer A are on the same switch. So the firewall would only be necessary for internet access. Am I correct?

Thanks,
Tray

 

[mlconley]

Well, I'm still having a little trouble visualizing exactly what your setup is, but I think that if you set the netmask on both computers to 255.0.0.0, they will talk to each other. With the netmask on the router set to 255.255.255.0, it will communicate with computer B, but will see computer A as being on a different subnet.

Likewise, computer B will still be able to communicate with the firewall because it is on the same subnet, but the firewall will not communicate with computer A becuse the firewall netmask is (I assume) configured as 24 bit mask.

I am reasonably certain tha using variable-length subnet masks (AKA VLSMs) is the best solution to your very complex setup. You will still have a certain amount of security imposed by the netmask values on the router/firewall.