search for: tcp_window_scaling

...of our firewalls I am having to disable tcp window scaling to stop network connections grinding to a halt. I am also trying to Kickstart CentOS 5 machines through the firewall so need to disable window scaling at install time. I have added to the kickstart file %pre echo 0 > /proc/sys/net/ipv4/tcp_window_scaling But the install still hangs while transferring the stage2.img Should the above %pre work or do I need to do something else to disable window scaling during the install. In case anyone's interested CentOS 5 is the first time we have suffered this problem both CentOS 3&4 worked without iss...

https://bugzilla.mindrot.org/show_bug.cgi?id=1697 Summary: scp transfers from remote cygwin machine fail with ssh versions >= 4.6 Product: Portable OpenSSH Version: 4.6p1 Platform: ix86 OS/Version: Linux Status: NEW Severity: major Priority: P2 Component: scp AssignedTo:

...ket every 5 seconds. What would cause that kind of throttling behavior? If I restart icecast it works for a while, then locks up again. I've had reports that it happens with windows icecast2 sources as well, but I wasn't able to get a tcpdump of it happening for them. I tried turning off tcp_window_scaling on linux, in case it was hitting a bug in XP, but no luck there either. Oddities: I tried setting the server to the lowest priority in linux, then running a few CPU hogging programs. That didn't cause a noticible difference. Ideas where to look? -------------- next part -------------- An HTML...

Sysctl Values ------------------------------------------- net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.tcp_window_scaling = 1 # vm.max-readahead = ? # vm.min-readahead = ? # HW Controler Off # max-readahead = 1024 # min-readahead = 256 # Memory over-commit # vm.overcommit_memory=2 # Memory to activate bdflush # vm.bdflush="40 500 0 0 500 3000 60 20 0" -------------------------------------------- What...

We use SMB to transfer large files (between 1GB and 5GB) from RedHat AS4 Content Storage servers to Windows clients with 6 DVD burners and robotic arms and other cool gadgets. The servers used to be Windows based, but we're migrating to RedHat for a host of reasons. Unfortunately, the RedHat Samba servers are about 2.5 times slower than the Windows servers. Windows will copy a 1GB file

...ket every 5 seconds. What would cause that kind of throttling behavior? If I restart icecast it works for a while, then locks up again. I've had reports that it happens with windows icecast2 sources as well, but I wasn't able to get a tcpdump of it happening for them. I tried turning off tcp_window_scaling on linux, in case it was hitting a bug in XP, but no luck there either. Oddities: I tried setting the server to the lowest priority in linux, then running a few CPU hogging programs. That didn't cause a noticible difference. Ideas where to look? -------------- next part -------------- An HTML...

...nksys), each giving connection for every eth2 "C" class Along a week I''ve changed my syslog.ctl like: net.ipv4.ip_forward = 1 net.ipv4.icmp_ignore_bogus_error_responses = 1 net.ipv4.icmp_echo_ignore_broadcasts = 1 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_window_scaling = 0 net.ipv4.tcp_sack = 0 net.ipv4.tcp_fin_timeout = 30 net.ipv4.tcp_keepalive_time = 1800 net.ipv4.tcp_low_latency = 1 net.ipv4.tcp_ecn = 0 net.ipv4.conf.all.accept_source_route = 0 net.ipv4.conf.all.accept_redirects = 0 net.ipv4.conf.all.log_martians = 1 net.ipv4.ip_conntrack_max = 8192 net.ipv4....

...rnel.shmall = 4294967296 ########### add by operation V1.0 begin ############ net.ipv4.ip_local_port_range = 32768 65000 net.core.rmem_max = 8388608 net.core.wmem_max = 8388608 net.ipv4.tcp_rmem = 4096 87380 8388608 net.ipv4.tcp_wmem = 4096 65536 8388608 net.ipv4.tcp_max_syn_backlog = 8192 net.ipv4.tcp_window_scaling = 0 net.ipv4.tcp_sack = 0 net.ipv4.tcp_timestamps = 0 kernel.panic = 5 vm.swappiness = 51 ########### add by operation V1.0 end ############ net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 #add by wdh #net.ipv4.conf.all.pr...

I have been using BackupPC via rsync daemons on the target machines and all has been working well. At least until about the time rsync went to version 3.0.6. Since then backups have been failing for some targets. The failure is a TCP ZeroWindow issue. It looks like the server rsync process cannot empty it's buffer soon enough and eventually the process fails. I really do not know if it is

I haven't been able to find any information about this problem, I hope someone can help, anyway this is the setup: Server: - Linux Fedora Core 5 - kernel 2.6.17-1.2145_FC5smp - openssh-server-4.3p2-4 Client not working: - Linux Fedora Core 5 - kernel 2.6.17-1.2145_FC5smp - openssh-clients-4.3p2-4 Client working: - Same machine - Windows XP - putty 0.58 This is the log from the non working

...ckup server can handle 100x that amount of network I/O). All my investigations seem to point to a TCP stack problem, but that's about as far as I can get. I've found a solution that works for me - turn off TCP window scaling on the backup server. This can be done using sysctl -w net.ipv4.tcp_window_scaling=0 There is some discussion of TCP window scaling problems at: http://lwn.net/Articles/92727/ but these discuss broken routers. My server and client are on the same subnet, so it's not exactly the same issue. Turning off window scalling is probably not a good solution in general, but it'...

I have a very odd problem connecting to some websites from my CentOS 5 box Target websites: www.connecttech.com www.3ware.com (two of my HW vendors) I can usually get some kind of response, but if the content (download or page itself) is larger in size (downloads never pass 100K), then it hangs... When I fire-up wireshark, I get a lot of ougoing highlighted Checksum Errored packets but I

Hi! I have a really weird problem with some of my servers, namely all the ones running Centos5 When I try to download a file from the server to a machine outside our Cisco 6500 router/firewall, the download hangs about half the times (15 out of 40) when less than half a megabyte into the transfer (varied from 76 kb to 496 kb). One server has a portchannel (Cisco speak for ethernet bundle),

...end/recieve windows on my systems. There's articles > out there. I don't have historical references handy. > YMMV. > net.core.wmem_max = 1048576 > net.core.rmem_max = 1048576 > net.ipv4.tcp_wmem = 4096 65536 1048575 > net.ipv4.tcp_rmem = 4096 524288 1048575 > net.ipv4.tcp_window_scaling = 1 > > Regards, Doug > > > I wanted to follow up to my email to provide at least a partial answer > > to my problem. > > > > The stock RedHat AS4-U3 Samba config has SO_SNDBUF and SO_RCVBUF set > > to 8k. With this value, I can transfer a 1GB file in about 7...

Configuration: (2) Dual Core Opterons 8GB RAM Apache used to balance 40 mongrel instances We receive Application 500 Errors. Nothing suspect appears in the log, so we are at a lost as to what to do next. Any advice would be welcome and/or an explanation of what types of things cause Application 500 Errors in mongrel. Thanks! - Jared Brown -------------- next part -------------- An HTML

I have AT&T (formerly SBC) DSL for my primary internet connection here, and tonight it has been exceptionally, extraordinarily S - L - O - W.... Pages that normally load in, at most, seconds, are taking several minutes to locate, even common, frequent access pages like Google, Gmail, etc. I called AT&T, of course, and all they know about is IE, which, as you can probably guess, I rarely

...roller: Matrox Graphics, Inc. MGA G200eW WPCM450 (rev 0a) /etc/sysctl.conf changes: net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 2621440 16777216 net.ipv4.tcp_wmem = 4096 2621440 16777216 net.core.netdev_max_backlog = 250000 net.ipv4.route.flush = 1 net.ipv4.tcp_window_scaling = 1 vm.dirty_writeback_centisecs = 50 Has anyone else seem similar issues? I can provide additional details about the server/configuration if anybody needs anything else. The issue only seems to occur under high write load as we've restored some of these backups and didn't seem to have...

https://bugzilla.netfilter.org/bugzilla/show_bug.cgi?id=443 ------- Additional Comments From nothingel@hotmail.com 2006-02-08 05:35 MET ------- I also, the situation described in bug ID 322 seemed related and I tried the patch from Phil Oester but it did not make a difference. -- Configure bugmail: https://bugzilla.netfilter.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving

...isn''t used, qdiscs default. I don''t realize what the problem is and even how to debug it. Sysctl config: net/ipv4/ip_forward = 1 net/ipv4/icmp_ignore_bogus_error_responses = 1 net/ipv4/icmp_echo_ignore_broadcasts = 1 net/ipv4/tcp_syncookies = 1 net/ipv4/tcp_timestamps = 0 net/ipv4/tcp_window_scaling = 0 net/ipv4/tcp_sack = 0 net/ipv4/tcp_fin_timeout = 30 net/ipv4/tcp_keepalive_time = 1800 net/ipv4/tcp_low_latency = 1 Thanks for any thoughts. _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://...

Hi again, I keep posting about my problem with HTB -> http://mailman.ds9a.nl/pipermail/lartc/2005q3/016611.html With a bit of search I recently found the exact same problem I have in the 2004 archives with some graphs that explain it far better than I did -> http://mailman.ds9a.nl/pipermail/lartc/2004q4/014519.html and http://mailman.ds9a.nl/pipermail/lartc/2004q4/014568.html