Hi,

Here's the situation, I have two network cards in my Windows 2003 RS2 (Small Business) and two routers, I plan to have it set up so that we have a fall-back if the internet on the primary router were to drop out or loose connectivity to the internet, so that we will not loose connectivity or outside requests for applications running on our server.

At the moment my configuration is this:-

Network card 1:
IP: 192.168.0.5
Sub: 255.255.255.0
Gateway: 192.168.0.1

Network Card 2:
IP: 192.168.0.4
Sub: 255.255.255.0
Gateway: 192.168.0.2

What is the best way to achieve this? At the moment the workstations default gateway all go directly to the router, is it better to direct them via the server so they can benefit from a multi-homed connection?

Thanks,

Dean

I forgot to add:-

With my current configuration I have some weird things going on, such as I cant ping 192.168.0.4 nor point router port forwarding on to this IP, so I assume there is something slightly wrong in my setup!

You would be better off disabling your 2nd internet connection until needed.
Or leave it unplugged and plug it in when needed.

You can screw around with trying to make a backup route, but generally you would do that at the Network level, not the software/server level.

Sorry, but as there is not someone to sit around and monitor connections 24/7 and we need fall-back for inbound I need a solution to this rather than "Unplugging the cable"

You would need to purchase a high-end router and configure it to use an alternate path if the first path failed - First path ISP #1, second past ISP #2. With that, you wouldn't need the 2nd NIC in the server.

If you plug them both in, the server will take a path to use as a connection to everything. If the server has to switch NICs to get inbound traffic, it'll have to drop a connection to everything attached to it.

Thus, you'll want to pick up a network device to do the routing for you. You could go with something like Network Load Balancing, which you might be able to use with Windows Server.. it'll install on the server itself. Though, in my position, we have our ISP load balance for us so we don't have to configure it.

But you're looking at a high end router.. Cisco comes to mind.. I can't think of the other brand that might be easier to use.

You may be able to find a dual WAN Linksys Router which may resolve your problem as well.

http://www.speedguide.net/broadband-view.php?hw=34

No no no no, you don't.

I was working on the same thing just recently, and figured out how to do it in windows server 2003. And it's working just fine.
Make sure you either have or can install Routing & Remote Access (should be in Administrative Tools)
If you need to install it, just do so with basic NAT/Firewall checked (one of the options required to install RRAS - Routing and Remote Access Service), but we're not going to use NAT.

Remove your gateways from your adapters (by going to your NIC->TCP/IP Properties->Advanced->Gateways->Remove (hopefully you can get my drift))

In the RRAS snap-in, right click on Static Routes and add a new route.
(I'm going to assume that your LAN connections are named "Network Card 1" and "Network Card 2" respectively for ease of typing)
Set this up:
Interface: Network Card 1
Destination: 0.0.0.0
Network mask: 255.255.255.255
Gateway: 192.168.0.1
Metric: 1

Click ok, and right-click "Static routes" and add another new route:
Set this up:
Interface: Network Card 2
Destination: 0.0.0.0
Network mask: 255.255.255.255
Gateway: 192.168.0.2
Metric: 1

Click "OK" and then right-click on "static routes" and click "show ip table"
make a note/screenshot of it as it is now

Go back to your network adapter properties, go to the "Network Card 1" properties
Go to TCP/IP Properties->Advanced->Gateways->"Add"
Gateway: 192.168.0.1
Automatic Metric: UNCHECKED
Metric: 20
Close out of that

go to the "Network Card 2" properties
Go to TCP/IP Properties->Advanced->Gateways->"Add"
Gateway: 192.168.0.2
Automatic Metric: UNCHECKED
Metric: 20

Now get a new list of the routes in your IP routing table by going into the RRAS snap-in, right click on "static routes" and click "show ip routing table"
You should have at the top, something like this (the first 4 lines are the critical ones, if these aren't right, re-try the order in which you setup the static routes & add the gateways)

Destination Network Mask Gateway Interface Metric Protocol
0.0.0.0 255.255.255.255 192.168.0.1 Network Card 1 1 Static (non...)
0.0.0.0 255.255.255.255 192.168.0.2 Network Card 2 1 Static (non...)
0.0.0.0 0.0.0.0 192.168.0.1 Network Card 1 20 Network Mgmt
0.0.0.0 0.0.0.0 192.168.0.2 Network Card 2 20 Network Mgmt

Be sure to make your destination NAT on your routers MATCH from router to IP resepectively, or the whole thing won't work, ie:
router: 192.168.0.1 needs to forward traffic to 192.168.0.5
router: 192.168.0.2 needs to forward traffic to 192.168.0.4

Essentially what you're doing is bonding a gateway to a NIC. This may work for you, it has definately worked for me when I needed to setup a web server that would respond on 2 different public IP's.

-Some

OMG somenon. You saved my sanity! I have been wrestling with this problem for a month. Thank you!

I'll tell you my problem so it may help others.

I have same setup windows 2003 server. Two NIC card, one answer request to one gateway and the other answers to another gateway. For some reason one nic keeps locking up. It still receives packets but doesn't send. Disabling and re-enabling the card make it works for about 15 min and down it goes again. This solution worked like a charmed. Solid.

Again thanks