On 8/25/06, Matt Morgan <minxmertzmomo@xxxxxxxxx> wrote:
On 8/25/06, Jay Cliburn <jacliburn@xxxxxxxxxxxxx> wrote: > Matt Morgan wrote: > > I'm having a new (to me), strange networking problem on an FC5 install > > on a new computer. Basically, I can't make some network connections to > > some sites. The best way to explain this is probably with some > > examples: > > > > 1) I can ssh to my own server. > > 2) I can http to my own server, but I can't download the image on my > > home page (a very small png). Nor can I get the squirrelmail home page > > to load from that server. > > 3) I can login via IMAP to my own server, but then Thunderbird times > > out when downloading mail. > > 4) I can login via POP3 to my ISP email account, but then Thunderbird > > times out when downloading mail. > > 5) I can get to any google web site, like my gmail, and to > > register.co.uk via http, but I can't download slashdot pages or New > > York Times pages or most other web pages (timeout on "Waiting for > > /server/"). > > > > In all the cases of failure, it's not DNS--I get the address fine. > > > > On the same computer I have a Windows XP install, where all these > > things work fine. So I know it's not hardware. For what it's worth, > > everything worked fine for a about a day and a half before I lost some > > networking. I'm clueless as to what might have changed since it > > worked. > > > > The network adapter is an SiS 190, which is historically problematic > > in Linux, but I thought it was all supposed to be worked out in FC5. > > System-config-network calls it a "Silicon Integrated Systems [SiS] > > Unknown Device 0190," though, which doesn't sound good. > > > > I have seen links to an SiS-provided driver for the 190 that I can > > compile and install (eg > > http://www.cse.iitb.ac.in/~mohitz/tech/lan.php) but they look old > > (kernel 2.6.9 era). Is there some easier/more current way to get it > > working on FC5? I checked this list for help, and I don't see any > > complaints about this adapter since FC3 ... > > > > Thanks, > > Matt > > > > You didn't specify what kernel you're using, but these symptoms sound > like a TCP window scaling issue. TCP window scaling was changed in > 2.6.17, and certain middleboxes in the network pathway to your > destination sites might not be able to handle it. FreeBSD systems are > also susceptible. Google for details. > > Become root and issue this command, then retry your connections. > > sysctl -w net.ipv4.tcp_window_scaling = 0 > That sounds extremely likely ... I bet what happened was that it worked fine on the install (from CDs) and then I updated the kernel right away, but didn't reboot for a day or two. So when 2.6.17 kicked in ... I can't check it until tonight, but I bet you nailed it. Thanks.
OK, I spoke too soon. That setting did not help; I also tried going back to kernel 2.6.15 and that didn't work either. So this does not seem to be the issue. Any other thoughts? Thanks, Matt
