Posted 15 February 2010 - 05:18 PM
Great ! It looks like we can do this the easy way.
Here is what is going to happen. We will combine your two "inside" networks into one physical network with each gateway providing a way out. Then we will set your business computer to a Static IP and it's gateway to the business router. Your personal router will manage all DHCP (and probably all wireless activity) for any other computers that may live or visit your place, providing the IP of the personal gateway. Anything should be able to access anything locally (depending on normal OS security), but the business machine will use the business gateway exclusively for any communication outside the local LAN, and everything else will use the Personal gateway. Does this sound like what you have in mind ?
If so, proceed, if not, let me know.
You may want to read through this before starting, just so you know what you are getting yourself into.
Virtually all of the changes will be on your business router and PC, and since I don't happen to have a ST585 handy I'm flying a little blind. If things don't seem to be going according to plan STOP and let me know.
First of all, we need to make your business router just a little bit less intelligent. Log in to the router and back up or write down the current settings on each page you can get to. We aren't going to touch the service provider (WAN) side, but it is the most critical, so don't miss it.
Now we will turn off the wireless portion of the router, if it hasn't been already. This should be under Home Network -> Device Settings or Home Network -> Interfaces and we want to just disable the wireless.
Next we want to disable DHCP. This should be under Interfaces -> LocalNetwork and once again we just want to disable it completely.
Now we need to change the addresses that your router is using on the inside (LocalNetwork) so that they don't conflict with your other router. By default, it seems there are two active addresses, 192.168.1.254 and 10.0.0.138, both with a /24 mask (which is the same as 255.255.255.0 in dotted decimal notation). It looks like the default DHCP setup assigns addresses from 192.168.1.64 to 192.168.1.253, so we want to avoid that range. Even though we have turned DHCP off on this router once the two are connected together the other router will be assigning addresses. The addresses we will change your business router to are 192.168.1.1/24 and 10.0.0.137/24 so we don't conflict. When this change is made you will lose communication with the router, because it's address will have changed, so lets take a short detour to your work machine and set it up before we change addresses. That way you can log back into the router after the change from that machine.
On your work machine get into Control Panel -> Network Connections, select your Local Area Connection and then Properties, select Internet Protocol (TCP/IP) and then Properties again (phew). Now select Use the following IP address and set IP Address 192.168.1.2 , Subnet Mask 255.255.255.0, and Default Gateway 192.168.1.1 . Select Use the following DNS Server Addresses and enter 192.168.1.1 for the Preferred DNS Server. Hit OK and close things out back to your desktop.
Now get back into your router and go to Home Network -> Interface Settings -> Configure and you should see the current IP address on the left. Change 192.168.1.254 to 192.168.1.1, and 10.0.0.138 (if present) to 10.0.0.137. The subnet mask for each should be 255.255.255.0. Save.
The router will probably reboot at this stage. Once it finishes try to log on to it using your work computer. The router's new address should be 192.168.1.1. Check and see if you have good Internet connectivity. Good ? OK ! We are almost done.
Now we glue the networks together. This will take an Ethernet cable from the back of one router to the back of the other. It looks like the ports on that router are auto-MDX so any decent Ethernet cable should work, but if the lights don't come on you may need a crossover cable. A crossover has pins 1 and 2 on one end swapped to 3 and 6 on the other, and vice-versa. The local 'puter shop should have one, or anyone that deals with Ethernet a bit either has one or can whip one up for you. The cable should be from any of the LAN ports on one router to any of the LAN ports on the other. Only one cable please. Connecting two will introduce you a nice broadcast storm and the reason the Spanning Tree protocol exists, but unfortunately is usually disabled on SOHO routers and switches.
You will need to edit any port mappings on your business router to point to the new business computer IP address.
You should now have full connectivity between your local devices, with separation of access. You might want to make the Windows Workgroup name the same on all your machines just to make it easy. You can use any open Ethernet ports on either router for additions to your home network, and any wireless devices will also join the home network. Only if you add a static IP addressed device (in the range of 192.168.1.3 to 192.168.1.63) with the Default Gateway field set to 192.168.1.1 will it use the Business broadband access.
Let me know how it works (or not...)
And yes, I'm across the puddle. Oregon, actually. Almost got my feet in the Other puddle.