I've got a peculiar situation that I hope you all would listen to and offer feedback on any possible implementations. So I've recently broke down and purchased a DSL connection for my home computer, and I've just discovered the joys of p2p file sharing (i.e., being able to download television shows that my local stations have stopped carrying, like Enterprise). Anyway, as you can guess, these video files are rather large, and other users also grab them from my computer as well, so my upload speeds are rather high. Since I've subscribed to DSL service through a local ISP, and since local ISPs are big on service but not on resources, I got a call from them recently asking me to tone down my upload bandwidth usage on the DSL line. I've pretty much got to listen or I will lose my service. My local setup consists of a linux box acting as a gateway for my home network of (gasp!) one computer and a laptop. The linux box currently uses ipchains to perform the necessary IP masquerading for the connection. Some quick stats: eth0: external network connection (to ISP) eth1: internal network ppp0: modem attached, but not currently used. So here comes the question: since I've got to reduce my upload usage, I'd like to try to use the linux box to do a special form of SNAT routing. I would like all outgoing data to leave through the attached ppp0 interface (the modem which I can hook up to a dialup ISP) and all incoming data to come back in through the eth0 interface (the broadband connection to my local ISP). Basically, I need to do a form of SNAT routing that overwrites the source address of packets leaving on the ppp0 interface with the IP address of the eth0 interface, so when their replies come back the will come on the faster broadband connection. This way the upload bandwidth usage on the DSL connection will be effectively zero, while I will still be able to enjoy the fast download speeds of the DSL line, satisfying both me and the ISP. My issues include the current usage of SNAT routing (masquerading) since my local network connects to the internet through the linux box's one IP address, and how to use ipchains, iptables, or ipnatctl (or others) to perform this extra set of SNAT routing. Does anyone have any ideas on how to implement this? Sorry for the long story, and I thank everyone in advance for their time. Have a good one, Paul __________________________________________________ Do you Yahoo!? Y! Web Hosting - Let the expert host your web site http://webhosting.yahoo.com/
