W2K3 with 2 NICs and 2 ISPs strange problem.

[seba1976]

Hi,

I have two ISPs connected to the same PC running W2K3. The PC has two NICs adapters. This configuration is mainly for failover and redundancy. The problem I have is that W2K3 completely ignores whatever comes through the second NIC. It picks one as the default gateway, but ignores the packets coming from the other. I have, for example, Remote Administrator running on that PC, and it only answers when I get through the primary ISP. I've used a port sniffer (Wireshark) and the packets do reach the other adapter, just nobody respond to them.

Worst thing is, it worked flawlessly in XP for about a year, until I was forced to switch to W2K3. I'm really desperate here. I've already exhausted all the help from people I know and from broadbandreports.com. A dual WAN router is on my list but they are really expensive in my area, plus they are way too much equipment for the simple thing that I was able to do without it.

Any help?

Thanks in advance.

Seba.

 

[timby]

Do you have two modems, one from each ISP?

Do they have different default tcp/ip addresses (192.168.0.1, or 192.168.1.1)?

Are you using VPN to connect to work?

I'm trying to get a little background to see if I can make a reasonable suggestion on what you might try next.

 

[seba1976]

Yes, I have two modems, one is in bridge mode, so the NIC connected to it has a public static IP. And the other is in route mode, so the NIC connected to it has a local IP, like 192.168.1.200. They both have their default gateways configured. Besides, if I unplugged the cord from the NIC that W2K3 responds to, the other one starts to work about a minute after, and I can even remote from the box through it.

I'm not using anything VPN related.

Seba.

 

[ohiou_grad_06]

I wonder, if you have 2 modems, could you take 2 those 2 wires, run into this....

http://www.videkonline.co.uk/home.asp?page=SubSections&sectionID=42&chapterID=4

Look toward the bottom of the page at the y splitter for the patch panel, run your cords into that, that single line into your router, and your single out from your router into your single card?

 

[seba1976]

I've been reading the product overview, and it looks like it is intended for something completely different. It takes advantage of the fact that not all the pairs are used by networking equipment, and then use them to carry aditional signals. Though I'm not sure about what the router will do with the unused pairs -now carrying live signals-, I think it will most probably ignore them.

 

[ohiou_grad_06]

Yeah, it was an idea, but if you could find a splitter of some kind, maybe a coupler with 2 ins and one out maybe that would do it for you.

 

[bravo29]

What kind if nics are in the PC's? Check if the nics offer a software to handle this. Its like the HP broadcom card software. I can either team them, fail over or act as one.

 

[seba1976]

The NICs are of two different brands. One is a Encore 10/100 Mbits generic adapter, plugged in a PCI slot; and the other is an onboard Intel 82566DC 1 Gigabit speed. Do you know if there is some kind of software like you said for this adapters?

I appreciate your concern.

 

[bravo29]

If you have the funds I would look into a broadcom dual 10/100/1000 nic or an Intel. You can get one from ebay or retail for about $100. Broadcoms drivers come with a the software to do this.

 

[seba1976]

Dual NICs... I didn't know they existed. Thanks, I'll look into that. Does anyone have any clue about why it worked out of the box in XP but not in W2K3?

 

[riser]

Disable Internet Connection Sharing if you have it enabled. That will screw up some dual NICs on a server.

One NIC is functioning properly. What kind of commands are you sending to your other NIC to test it?

Unless otherwise specificed, only one NIC will be used to send data. Receiving is another story but what might be happening is that your NIC is receiving the information and when sending the ACKnowledgement, its sending it via the other NIC/ISP and the data isn't all getting there. That's a guess though..

Why are you trying to run 2 ISPs though? If one goes down, the other most likely will go as well since they're both sharing the same lines to a point.

The idea of having 2 NICs was one for external and one for internal use. If you want redundancy, you're better off disabling one or strictly using only one via DNS or port forwarding. If one doesn't work, have the second one send it by DNS. Port forwarding would allow you send all signals to one NIC and if that doesn't work, have it send to a second NIC.. but expect some short downtime while making that switch.