Red Hat Bugzilla – Bug 129204
184.108.40.206.494.2.2 Kernel Networking Problem
Last modified: 2015-01-04 17:08:28 EST
Description of problem: My FC2 computer is on a LAN with Win98SE and
Win2k computers. Often I transfer files from the Win computers to the
FC2 computer. I have Samba 220.127.116.11 installed.
I use the Nautilus file browser to open a window for the share on the
Win computer, open another window for a directory on the FC2 computer,
and simply drop-and-drag files from one window to another. This works
fine for kernels up through 2.6.6-1.435.2.3
Recently I installed the new 2.6.7-1.494.2.2 kernel. Now, when I try
to drop-and-drag files, the "copying files" window freezes. When I
reboot with the older kernel, I can transfer files as before.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. see above
Actual results: file transfer freezes
Expected results: normal file transfer
I have spurratic TCP hang problems with the new kernel
(2.6.7-1.494.2.2). My Mail client hangs when getting mail, my browser
hangs when loading web pages, my ssh client hangs when typing
commands. Downgrading to 2.6.6-1.435.2.3 solved the problem.
*** Bug 129136 has been marked as a duplicate of this bug. ***
*** Bug 129135 has been marked as a duplicate of this bug. ***
Getting the same problem here, a bunch of TCP connections that worked
fine under kernel-2.6.6-1.435.2.3 are now broken under
kernel-2.6.7-1.494.2.2. For instance, I normally have several SSH
sessions open (to Linux and FreeBSD boxes). Some of those no longer
work, the SSH client hangs before ever authenticating.
Please see this thread for a possible fix:
Worked for me, too. ;-)
This does "fix" the issue I was having. However, I didn't have to set
both of the variables, just the following one:
Thanks for finding this solution.
This solved the file tranfer problem I originally reported.
Thanks so much. This is what I love about the open source community.
Open Source Rocks!
Solved my wget and curl problem too. However, the bug still exists
For the benefit of others who don't want to look through other threads
can do the following:
Add the following to /etc/sysctl.conf and reboot:
# The following solves a kernel networking problem with kernel-2.6.7-
1.494.2.2, kernel-2.6.8-1.521. If you finally do not need
it, just comment them with a leading #.
net.ipv4.tcp_default_win_scale = 0
this thread is similar to
more info at http://lwn.net/Articles/91976/
mass update for old bugs:
Is this still a problem in the 2.6.9 based kernel update ?
I no longer have an FC2 system to test with (they've both been
upgraded to FC3), but FC3 no longer appears to have the
$ uname -r
$ /sbin/sysctl net.ipv4.tcp_default_win_scale
error: 'net.ipv4.tcp_default_win_scale' is an unknown key
Everything does appear to work fine, though.