Here's a message that I originally sent to some Linux ISP mailing lists. I believe that it may be suitable for this list.
Russell Coker ------------------------------------------------------------------------- The following message is forwarded to you by [EMAIL PROTECTED] (list as the From user of this message). The original sender (see the header, below) was [EMAIL PROTECTED] and has been set as the "Reply-To" field of this message. ------------------------------------------------------------------------- From: [EMAIL PROTECTED] Date: Sun, 18 Aug 96 22:17:56 -0500 To: [EMAIL PROTECTED], [EMAIL PROTECTED] Subject: Re: [linux-support] Access to 1.2.8 from 2.0.6 In-Reply-To: <[EMAIL PROTECTED]> Cc: bofh In <[EMAIL PROTECTED]>, on 08/17/96 at 01:57 AM, Mark Lane <[EMAIL PROTECTED]> said: I am having a problem which may be related. I'm running a small ISP and an Internet cafe. I have 2 servers a Debian system and a Slackware system. Dial-up users who are unfortunate enough to be using Windows 3.1 and trumpet or Win95 are the only ones affected (users of OS/2, Linux, and NT have no problems). What happens is that when they establish a TCP connection to the debian system data will be transferred very slowly. I have both the Slackware and Debian systems running as PPP servers and no matter which one the poor Windows user connects to they will get very poor throughput when transferring data to the Debian system. So if a user connects via PPP to the Debian system and then transfers data to the Slackware system then everything will be fine. Obviously the Debian system is routing IP packets correctly, but there is some problem with TCP (could be MSS). I have taken the Debian system from version 0.96R3 (a.out) with kernel ~1.3.60 to 1.1 (ELF) with kernel 2.0.13 and it made no difference. If you know what I could do (or even some useful tests I could run to get more information) then please let me know. > I recently installed a Debian 1.1 system with the 2.0.6 kernel. >I couldn't have asked for a smoother install from a Windoze package, so >kudos to the development team! Had one glitch with Majordomo 1.93, but >that's another e-mail sometime :) Now, onto the real problem.... > I am having problems accessing data (ie. mail, web, etc.) on a >pre-existing (prehistoric?) Slakware 1.2.8 host from Mac/FreePPP and >Win95 PPP clients of the Debian host. Win31/Trumpet clients work just >fine. For example, I can establish a PPP connection from a Win95 client >into the Debian box, TELNET into the Slakware box, type 'ls /tmp', and >get a file listing (only a few files). However, if I transfer more data >(ie.'ls /etc' or 'w'), >the output hangs. I cannot retrieve web pages from the Slakware server, >nor access mailboxes NFS-mounted on Debian from Slakware. Anything that >appears to transfer much data back to the PPP client (through the Debian >host) hangs. All this *seems* to work fine going the other way (PPP to >Slakware then access Debian), but I haven't tested enough to be sure (at >2am things get fuzzy). I suspect a MTU/MSS problem. > The only odd thing I can see is a difference in the maximum >segment size on the Debian and Slakware hosts. Slakware shows MTU of >576 and MSS of 512 for PPP devices, where Debian shows 576 for both. >Same for the ethernet device (1500MTU on both, 1436MSS on Slakware and >1500MSS on Debian). I used ifconfig to change the MSS on Debian's eth0 >device (didn't know how to do the same on PPP devices) and recompiled the > kernel to disable MTU path disocovery to no avail. I'm at a loss, and >hope someone on this list has already come across this. I can send any >configs or test results necessary to diagnosis. I'd sure appreciate any >insight out there on this! > Th >k you, > Ma >-------------------------------------------------------------------- >Mark S Lane ([EMAIL PROTECTED]) | >3rd Wave Technologies | >Phone/FAX: (423) 652-6090 | >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >To un-subscribe to this list, send requests to [EMAIL PROTECTED] with the >body of the message stating: unsubscribe linux-support. Please send >postings to: [EMAIL PROTECTED] Problems: [EMAIL PROTECTED] ----------------------------------------------------- -- End of forwarded message ----------------------------------------------------- -- ----------------------------------------------------------- [EMAIL PROTECTED] -----------------------------------------------------------
