Connection tweaking needed

arrruken · 05-26-2003, 10:27 PM

Ok I have DSL, and a router to share the connection of my two computers. now the problem is i cant access web mail or use forums when connected through the router. but i figured out the problem and fixed it in windows. I had to use a program called DrTCP, a gui tool for editing the registry, to increase my MTU and some other settings. now it works fine through the router in windows but not in linux. Does anyone know of a tool or where to look to change similar TCP properties in linux, specifically slackware 9.

unSpawn · 05-27-2003, 10:15 AM

None I know of. Even tho it's definately unholy to even *think* of comparing, you could compare parts of the registry to /proc on Linux. Settings that affect networking like TTL, MTU etc etc are in /proc/sys/net/ipv{4,6}. Using the docs under /usr/src/linux/Documentation/ about proc and networking you could easily tweak stuff. Once you get it right have a look at "man sysctl" for making changes permanent.

arrruken · 05-27-2003, 09:50 PM

thx i guess youre the only ones who knows about stuff like taht

Robert0380 · 05-28-2003, 02:59 AM

changing the MTU is quite an odd thing to have to do, 1500 is pretty much a standard and anything that gets transfered that's over the MTU just gets fragmented. It's all a part of the protocol. I guess this doesn't help answer your question, but I thought having to change the MTU is kind of a strange move. Was it just those network settings that had to be changed in Windows?

arrruken · 05-28-2003, 07:48 AM

i had to change something called the " tcp recieve window" and the mtu, for some reason the mtu was default at 1394, and while mtu for routers and such is default at 1500, most comps are at 1492, which is what i had to set it to.

Robert0380 · 05-28-2003, 11:24 AM

yea i know about the advertisement window, but again i have never heard of it having to be tweak. especially for email and news groups. that's another one of those low level things that TCP takes care of for you. I'm not sure, but I think if you want to change that kinda stuff in Linux, you may need to modify some kernel source code and re-compile the Kernel. Take a look at the Documentation for that, I've changed some TCP and UDP queueing stuff in the kernel for a project but never messed with the mtu or recieve window.