LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices

Reply
 
LinkBack Search this Thread
Old 12-01-2012, 03:57 PM   #1
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 231

Rep: Reputation: Disabled
OpenVPN replay-window backtrack occurred [1330]?


I've posted several questions on why my openvpn upload speed from my house runs at half the total bandwidth (paying for a 10mbps upload, every other service (http,ftp) maxes out this speed, but vpn transfers up max out at 4-5mbps??) but have gotten zero responses. I figured i'd try again.

I've started noticing a lot of this message:

replay-windows backtrack occurred [n]

where n is usually in the hundreds, but sometimes gets up into the thousands. i've looked this up and apparently it has something to do with dropped packets?

what exactly does this mean, is it related to the slowness, and how might I improve it?
 
Old 12-02-2012, 03:29 PM   #2
mmheera
Member
 
Registered: Oct 2012
Location: Germany
Distribution: Ubuntu, Debian, Fedora,Windows 7
Posts: 107

Rep: Reputation: 11
Many people has complained similar issues. But I Guess, it has something to do with the latency or congestion of that particular connection to the VPN server. While every other services are working fine, then there must be a congestion at the vpn link. It can happen because of cpu load also. It is not always a problem with OpenVPN. You can, if possible, try the same link with other vpn, i.e. IPSEC and check.

There have been suggestions, since the problem is caused by using the UDP protocol, one can switch over to a TCP protocol instead. May be you can try to change the client configuration and see if it helps.

Here is an explanation to the error you are seeing:

http://openvpn.net/archive/openvpn-u.../msg00068.html
Here are some troubleshooting tips:

http://www.personalvpn.org/troubleshoot_openvpn.htm
http://support.real-time.com/open-so...vpn/index.html

Thanks!
 
Old 12-07-2012, 01:42 PM   #3
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 231

Original Poster
Rep: Reputation: Disabled
thanks for the links. unfortunately these pages don't give any useful information on how to improve the speed, thought they do somewhat explain the reason behind these errors i'm getting.

my problem is that the speed is always slow, regardless if i am getting these messages or not. I can connect at my work or other places with a hardline ethernet directly into a router on a remote connection that gets >20mbps down, but I still only get 3-5mbps of actual sustained VPN transfer to the remote location. this makes any work with files larger than several megabytes essentially unusable - it feels like i'm on a dialup connection.

speedtest.net shows that I definitely have 50mbps down/10mbps up at the server.the specs of the server are:

Intel Core 2 Duo 2.4GHz
2GB RAM
Gigabit PCI-E intel ethernet adapter
 
Old 12-12-2012, 06:03 PM   #4
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 231

Original Poster
Rep: Reputation: Disabled
well, kinda solved. just switched to using FTP over the openvpn and speeds are back to normal.... samba is slow I guess? over higher latency connections at least...
 
Old 01-30-2013, 10:26 PM   #5
skyrider
LQ Newbie
 
Registered: Jan 2013
Posts: 1

Rep: Reputation: Disabled
Psy, I ran into the same problem you did when using samba shares through openvpn. I was looking into transfer speeds through openvpn (UDP) and found cifs shares to only do a little over half the speed of nfs shares. I found SSH, FTP, and NFS to use the full speed of the link.

Likewise, I found an IPSEC VPN (OpenSWAN) to only transfer about half the speed of OpenVPN, even when using the same encryption algorithm. All of this was tested on an isolated LAN where other traffic and network delays were not an issue.
 
Old 01-30-2013, 11:24 PM   #6
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 231

Original Poster
Rep: Reputation: Disabled
yeah, so i've seen. as well, i've recently figured out that some windows 7 machines (mainly laptops) have a power management setting that throttles down the CPU speed. i've recently turned this off and have seen restored consistency to openvpn using the full bandwidth available. on my win7 laptop the power setting is called "proccessor state power management" or something.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] Backtrack 5 R1 with ATI Radeon HD 6850 - Window redraw lag bagstoper Linux - Desktop 2 01-17-2012 05:58 AM
startx is not working when i installed rhel5 in dell xps 1330 laptop popvij Linux - Newbie 4 05-11-2009 07:57 AM
Dell XPS 1330 Wireless Card Not working KinnowGrower Linux - Laptop and Netbook 6 10-12-2008 04:26 PM
Sound via loud speackers on dell xps 1330 PocketSam Suse/Novell 2 04-24-2008 01:48 AM
D-Link WMA 1330 Drivers for REL-5 HBN Linux - Networking 14 08-16-2007 04:31 PM


All times are GMT -5. The time now is 02:10 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration