Very Slow Network

Hello there

      I just performed a clean install of openSuse 11.4 x86-64. So far it works great except... the network seems to be randomly slow and fast.

      I have disabled the IP6 protocol in both sysconfig and firefox. That helped with name resolution delays but many other problems still remain... 

Let me list the symptoms:

   I will start an ssh session and the first 5-6 commands will be really responsive. Then halfway through typing the next command it will hang for about a minute. When it comes back whatever keystrokes typed after the hang are echoed back. It is just a pain to be editing a text file remotely or ls'ing through a directory and constantly waiting for all those results a minute at a time.

  I will load a web-page lets say bbc news. Content will start to download quickly, the page will be half loaded then seeming stall halfway through and I will be looking at a message "Transferring data from new.bbc.co.uk" it will just hang for about a minute then all of a sudden the remainder of the web-page will all load at once. This problem happens on all websites. Again it is a problem where say 3-4 pages will load without delay then all of a sudden the 5th one stalls.

 I will be trying to connect to an external computer (ssh, yast software update, web-page) and it will give an error message that it cannot connect to host. Pressing retry (or re-enter the ssh command) and it comes up instantly immediately after. 

 Overall all these internet issues are intermittent. However it seems to happen every 5-6 requests for internet content. So it is frequently enough to be REALLY ANNOYING. 

  Another thing is I find that many of the delays effect all network content for all similar applications. For example if firefox is loading multiple pages once one hangs generally they all hang. Similarly when ssh hangs all other ssh sessions hang. Then when the hang stops all the web-pages and all the ssh command are loaded all at once. 

  I am positive this is a SUSE 11.4 problem. I am dual booting windows 7. On windows network traffic is VERY fast. putty (windows ssh client) is perfectly responsive no interruptions. Web browsing is instant. So it begs the question how do I achieve the same performance on suse?

 Furthermore I am sure this isn't a bad Internet day problem. I have been dual-booting both Suse and Windows for several days. It is fairly consistent that content on Windows is fast and on suse it is hanging intermittently. 

Request for help!!!

  Any suggestions on the source of the error or possible fixes will be greatly appreciated. 

  Since it is intermittent and not very repeatable it is difficult to debug (for example running ssh with -vvv options prints nothing when ssh hangs). Any suggestions on how to debug and track what is happening in detail will be greatly appreciated. 

Thanks
pilot

pilotmm wrote:
> I will start an ssh session and the first 5-6 commands will be
> really responsive. Then halfway through typing the next command it will
> hang for about a minute. When it comes back whatever keystrokes typed
> after the hang are echoed back.
[snip]
> I will load a web-page lets say bbc news. Content will start to
> download quickly, the page will be half loaded then seeming stall
> halfway through and I will be looking at a message “Transferring data
> from new.bbc.co.uk” it will just hang for about a minute then all of a
> sudden the remainder of the web-page will all load at once.
> Any suggestions on the source of the error or possible fixes will
> be greatly appreciated.
[snip]
> Since it is intermittent and not very repeatable it is difficult
> to debug (for example running ssh with -vvv options prints nothing when
> ssh hangs). Any suggestions on how to debug and track what is happening
> in detail will be greatly appreciated.

Perhaps stating the obvious but this seems like a network problem.
Perhaps you can tell us a little more about the topology? Your PC is
connected HOW, to WHAT? Are there any other ‘local’ machines on the same
network. How is the Internet connected?

How to investigate? I would start by looking at traffic monitors and CPU
monitors. Do you have a network applet in your panel? What is it
showing? Does your router make statistics available? What are they? What
does top show whilst the problem occurs? Do other programs continue
working during the problem (editor, video viewer etc)?

If there is no other local machine, try to put one on the network and
see if you have problems communicating with it.

HTH, Dave

Hi Dave

   Appreciate the help.

   At first I thought it was a network problem... like I said I have been dealing with this daily and in every instance a reboot into windows and all problems are gone. The network is managed by the University so I cannot tell you a lot there. Yet because it is managed by a professional I would think everything is in good order there... maybe not. Unless the network recognizes its a Linux computer and is giving its traffic a seperate treatment, will have to find out about that.

   So I just tried to ssh into the slow computer (from a reliable computer). I am getting the same intermittent stalls. I ran traceroute to the offending computer and identified a couple nodes where the delay is a bit longer than expected. I will pass this on to the sysadmin. Maybe they can help further. In the mean time I will moniter CPU and network stats see if something interesting pops up.

   Will report back when I know more. 

Take Care
Mike

Hello Dave (and others)

    Thanks for the help. I managed to solve the problem. It was the network driver. The r8169 driver is meant for the 8111B Ethernet chips not the 8111E I have. Downloading the latest from realtek was the fix. The network seems to be reliable now!!! Very pleased. 

Take Care
Mike

pilotmm wrote:
> Thanks for the help. I managed to solve the problem. It was the
> network driver. The r8169 driver is meant for the 8111B Ethernet chips
> not the 8111E I have. Downloading the latest from realtek was the fix.
> The network seems to be reliable now!!! Very pleased.

Glad you solved it! And congratulations on spotting the source of the
problem.