Posted by: BartDG
Networking question - 20/03/2005 14:50
Ok, here's the situation:
I've got both cable and DSL at home. I usually surf by cable, but since it's not entirely stable and reliable, I have the DSL connection in case it's down. Both cable and DSL are connected to my PC via ethernet.
Now, if the cable connection goes down, I simply disable (in software) the ethernet card through which the cable modem is connected, I turn on my DSL modem, dial in and voila: instant DSL connection.
But here's my question:
Now and then, the occasion arises where I could use both connections at once. Eg. I use bittorrent to download two huge files. I usually use the DSL for that because I've noticed it works better for these kinds of applications. This means the cable's ethernet card is disabled.
If I want to do any regular surfing now while I'm using Bittorrent, things are SLOOOOW. Now, my idea was, to enable the cable modem's ethernet card as well and surf via the cable modem. Unfortunately, this doesn't work because my browser obviously also tries to use the (already clogged) DSL pipe.
So, what I would really need is a program with which I could point out which application should use which ethernet card. Eg. Bittorrent ethernet card #1, Firefox ethernet card #2, and which would keep both connections competely separeted from each other.
Does such an application exist?
Thanks!
Posted by: drakino
Re: Networking question - 20/03/2005 16:02
While not directly answering your question, I used a
Twin WAN Router at home for a while for a cable and wireless connection. It works decently, and allows you to specify certain ports to always be routed out a certain ISP. The only reason I recently discontinued use of it was due to plans to get away from the cable company, but still haven't fully done so yet. In fact, I may look to sell mine soon if you are interested.
In theory a Linux router could do this too, but I spent many hours trying with no complete success.
Posted by: BartDG
Re: Networking question - 20/03/2005 16:15
Yes, I've also thought about this possibility, but this is not really the way I want to do this. First of all, you said it yourself, it doesn't do 100% of what I want it to do and secondly I don't really need another router right now. (I've alread got a few - don't ask...
).
And even if I were to buy that router from you, I would most likely have problems with the US 110 volts standard versus the European 230 volts standard. Too much trouble IMHO.
But thanks for your thoughts! Much appreciated!
Posted by: BartDG
Re: Networking question - 20/03/2005 16:53
D'oh! I knew that! (or should have anyway!)
Anyway, the hardware approach is really not the one I want to take. Let's just say it like that then.
Posted by: tfabris
Re: Networking question - 20/03/2005 21:05
Gotcha.
It's interesting that there's no built-in way in Windows (that I know of) to bind a specific application to a specifc ethernet card.
However, I think you could accomplish it all in software, simply by using a piece of personal proxy software. Have the proxy port-forward the desired ports to the correct upstream router. Essentially doing the same thing as the hardware router, only doing it within your PC.
Hm. Maybe this could even be done without third-party software using Microsoft's RRAS features. Not sure. But I think you need to have a Server version of the operating system before those features are available.
Posted by: andy
Re: Networking question - 21/03/2005 06:14
I don't think proxies are going to work generally on Windows. The root of the problem is getting Windows to talk to two default gateways.
As far as I know you can't do this on Windows, at least not out of the box. You might remember we had a previous thread where I attempted this and ended up with a setup where Windows would ramdomly switch backwards and forwards between the two default gateways.
I expect you might get it to work for things like web browsing. But only if the router itself has a web proxy on it. If you then had a proxy on the Windows box pointed at the web proxy on the router that isn't the default gateway, that would probably work around the default gateway problem for web traffic.
Posted by: wfaulk
Re: Networking question - 21/03/2005 18:57
We've answered this question many times before.
The problem is with the TCP/IP implementation. Virtually all implementations work by looking at the routing table and finding the best match for the destination address. There used to be an IP flag that would let the source determine the route used by the packet, but it occurred to virtually everyone that this is a security problem (it can be used to bypass NATs, for example) and has been almost universally disabled. Some anal ISPs drop packets that are source routed even if they aren't destined anywhere within their network. Anyway, that isn't going to help.
Fortunately, you're only interested in selecting what interface to use on your side. This is doable, but basically requires a new IP stack. The way almost all OSes work, even if you used interface A's address, it might still go out interface B's interface. (This can cause problems, too, with anal ISPs who think you're spoofing addresses.) So you need something that will specifically use one interface. This requires something that talks directly to the interfaces instead of letting the OS's IP stack do the job as normal. Since you want kind of a general-purpose thing that will work with multiple applications, this basically means you need a new IP stack, and that's not going to happen. (I don't think.) This is basically what happens on the Linux routers that will do what you want.
It's more likely that you can find a proxy server that will do what you want for web access only, but I still think the chances of finding one are slim.
Posted by: mlord
Re: Networking question - 21/03/2005 21:10
So don't do it at the routing table level.
Use iptables forwarding instead, telling it to forward bittorrent connections to one ip, and everthing else differently.
cheers
Posted by: wfaulk
Re: Networking question - 21/03/2005 21:15
Using iptables is pretty hard when you're not running Linux. I'm taking him at his word that he's using Windows, and he's already stated that he doesn't want another box.
Posted by: SonicSnoop
Re: Networking question - 21/03/2005 21:22
From the sounds of all this it probobly would be easier to just set up a POS pc for the dsl connection and just use it for surfing. I know its not the intended outcome, but it solves the problem.
Posted by: wfaulk
Re: Networking question - 22/03/2005 15:20
Okay, I guess I'm misreading what you said. I still am. Still, what I'm saying is what you meant, I think.
Actually, I have a process that's adding temporary static routes right now -- Azureus. I don't know *why* it's doing so, and it's causing problems with my VPN, but it's doing it, and would be working fine if my VPN client wasn't so anal. Of course, Azureus isn't doing it on anyone else's computer. Go figure.