I recently setup an old 300 mhz K6 computer to serve as a MASQ gateway for the other computers in my house. This MASQ gateway is connected to the Internet via a US Robotics ISA 56K modem. It's running RedHat 7.2 in pretty much virgin condition, and is setup to forward packets using iptables. This MASQ gateway box also serves as the DHCP server for every other computer on the network to ensure that they all get properly auto-configured to take advantage of the Internet connection. Right now, everything works beautifully. The MASQ gateway box is always left on and is always connected to the Internet (it has its own phone line). When I turn on any of the client computers in the house, they all get auto-configured for the network with their own IP and can immediately access the Internet. My problem comes when I use my personal Slackware workstation. When I turn it on, the ethernet card gets auto-configured by the DHCP server and everything works fine. I can then proceed to access the Internet. But while I'm using the Internet, there seems to be a major packet queuing issue which is preventing me from doing more than one thing at a time over the Internet connection. For example, if I'm downloading a 20 MB file from sourceforge.net, that single download takes up ALL of my bandwidth and leaves me with none for anything else. While downloading that file, I can't browse the web or check my email or start a download on another file, everything just times out and fails. The bandwidth is exclusively used for the file download and nothing else. However this behaviour seems to affect only my Linux-based clients. When I reboot my workstation into Windows XP (using the exact same hardware, since it's the same computer), this packet queuing issue disappears. While in Windows, I can be downloading 2 different files and still be able to browse the web AND check my email all at the same time. The bandwidth gets evenly distributed between all applications as needed. If I'm downloading one file at 5 KB/s, then begin a second download, then each download will get about 2.5 KB/s each. This is all through the exact same MASQ gateway box as the Slackware workstation was using. I would really like to be able to fix this problem since most of my work is done under Linux and not Windows. I've tried everything I can think of, but I just don't know where to begin to look for a solution. My MASQ gateway used to be running Slackware 8.0 and ipchains, and I was getting the same results. I thought that maybe changing over to RedHat 7.2 and iptables would fix the problem, but it hasn't. It's also worth noting that the same problem exists if I try to access the Internet directly with the MASQ gateway box. While I'm downloading a file from the Internet directly to the gateway box, then all bandwidth to the Internet gets sucked up by that one download, leaving none for any of the client computers (including Windows clients). I did once manage to get 2 downloads going simultaneously on my Slackware workstation, but the results were really weird. In Windows, when I have 2 downloads going at the same time, each download gets half the bandwidth in a very steady stream. But in Slackware, when I finally accomplished the feat of getting 2 downloads going simultaneously, each download would alternate between being stalled or downloading at full bandwidth. For example, the first download would continue at 5 KB/s for about 10 seconds, and then it would stall completely for the next 7 seconds. During that 7 seconds, the second download would proceed using the full bandwidth, then it would stall and it would be the first download's turn to get the full bandwidth again. I've read through the Advanced Routing HOWTO and followed some of the advice in there, but to no avail. I tried enabling SFQ on the ppp0 interface, and that changed nothing. I tried using an SQF qdisc from within a PRIO qdisc, and still that changed absolutely nothing (unless of course I'm doing it all wrong). Can someone please help me figure out what's wrong with my setup? I REALLY need to be able to do multiple things on the Internet simultaneously if I'm to work properly. It's bad enough I have to put up with a horrible dial-up connection in the first place, but this makes it unbearable :( I'll be eternally grateful if someone can help me fix this problem. Thanks in advance! Frank Gore (new list member)
