OK, here’s what gives. We have an extremely fragile Belkin wireless router that goes belly up everytime someone downloads a torrent or two. There are two machines connected wirelessly to the router and one (but also soon to be two) wired; thusly:
The wired and one of the two wireless are quite heavy P2P downloaders. Now, I was thinking: if I was to connect a switch between the router and the modem and connect the wired computer directly to the switch, that would diminish the traffic going through the router and hopefully put an end to our router problems, right? Actually, we did have a configuration of this sort some years ago. Sometimes the wired computer would dial in, other times the router would (our ADSL is PPPoE), and in both cases the Internet was always operational. But since the switch was borrowed, we had to return it after only a few days. Since then, our problems kept growing (occasional Net surfing slowly evolved to full-time P2P) until they recently became unbearable. Now, before rushing out to buy a switch, I did some research on the Internet as to how should I go about configuring the planned setup. Boy, was I surprised to find forums and threads convincing me that such a setup would never work! The reason: if your ISP does not give you multiple IP numbers (and mine doesn’t), there’s no way a switch can distribute WAN traffic to several computers, since, from the WAN side, they are all seen as one IP, i.e. as one machine. Now I know I actually had such setup working at some point in time! So, I’m asking networking gurus: who’s wrong here? Should I continue shopping for a cheap, sturdy switch to put between modem and router, or will that configuration never work as a number of forums keep telling me?
It depends on what the “modem” really is. Nowadays most “modems” are actually modem+router, but can be switched to bridge mode where they just pass through the external IP address and then another router handles the NAT to fan out to a LAN.
Maybe if you tell us what model your “modem” is? Does the “modem” have an IP address that can be used to configure it?
The modem is some obscure little white box about 10x5 cm (roughly 4x2") made by Iskra, model name EMX. I doubt anyone knows it. As far as I know it is a very rudimental box with no routing and no http interface whatsoever. In fact, the technician who installed it told me that we had such a bad phone line that “true DSL” just won’t work on it, so they installed this “bogus DSL” which can barely run 1024/256 (that’s why higher speeds are not available in our area).:\
In that case you need a router. If you have an old Pentium and 2 or 3 NICs handy you can set up a Linux router with a distro like IPCop and then run the wireless AP only for the wireless clients.
Minimum specs for IPCop: P100, 32MB RAM, 500MB HD. Lots of such machines or better have been tossed out. But you may wish to get one that draws as little power as possible, so avoid the high consumption CPUs like the P-II. CPUs with small or no fan are more likely to be low power. Disconnect all unneeded peripherals like CDROMs and floppies (after installation). You’ll be up for about 30W consumption.
One advantage of a Linux router is flexibility. For example you can run traffic prioritisation and shaping on such a router so the even with a heavy download going, you can still get a decent ssh response. Or configure it to prevent torrent from taking up 100% of your bandwidth.
Another possibility is if there is an embedded Linux for your wireless router, check dd-wrt or openwrt websites for supported models. Embedded Linux tends to be more robust and have more features than factory supplied firmware. But of course there is a non-zero chance of bricking your router in the process of flashing the embedded Linux on it.
Thanx for your concern, but you’re going well over my scope here. I have several constraints working against me: budget is of the essence, I already invested in the router and don’t intend to invest in my Internet/LAN any more if I can avoid. I got other interests in my life. Second constraint, our ADSL connection is located in my in-laws’ apartment downstairs; while they said nothing when we placed the modem and the router on their tiny telephone table, they surely wouldn’t be happy if I stacked another 10 m of cabling and an old noisy 386 box on top of that. I,m really looking for a neat, small-footprint and cheap solution here; it should also be configuration-free - I can’t keep busting in on them every time my setup dies (not surprisingly, it usually happens in the middle of the night). That’s why I’m looking explicitly for a very robust (while hopefully cheap) solution: that’s why I would never go with another router (at least not a cheap SOHO one). Thanx for your answers again, but I’d really like to know if such a setup (namely: modem–>switch–>router) is viable at all. Any suggestions? Anyone?
No, because you already gave the correct answer to your question. You only get one IP address from the ISP, and that cannot be shared between the router and your wired computer. So either get a decent router or make the torrent behave better, maybe you can limit the rate or the number of peers or something like that so that the router doesn’t fall over.
I see. The switch I had working years ago must have been one of those mixed-mode switches then? You know, operating at a combination of OSI levels 2 and 3 and having some routing capabilities built-in…
If I eventually decide to buy a new switch, I’ll post some feedback here for others that may have the same problem.
Thx for all the input, guys;)
P2P is probably a severe test for cheap routers because the large number of simultaneous connections requires more memory for tracking the connection state and network buffers. If you can find some way to limit the number of peers in your P2P software, maybe the router won’t fall over.
Remember some of these products are built to save every cent possible, so it might have 4MB of flash memory and say 8MB of working memory. Check the router forums for what people recommend.
