Today I had a problem when I lost network connectivity with an open TCP connecting (doing an FTP transfer). When network connectivity was restored, the TCP connection remained connected, but no data was being transmitted or received. Openning a new connection (using FTP reget) caused data transfer to recommence so there was clearly no problem talking to the remote machine.
I have also had similar experience when fetching a page or image with HTTP will stall, but aborting the transfer and reloading works quickly.
What I suspect is happenning here is that as a bunch or re-transmissions fail, TCP backs off for longer and longer before re-tranmitting and gets to the point that the time being waited is ridiculously long. What I would like to be able to go, both to test this theory and hopefully solve the problem of it happening, is to reset the backoff timer so it goes back to re-transmitting quickly. Does anyone now if there is way to do this on Linux?
Steve.
On Sun, 19 Aug 2001, Steve Fosdick wrote:
What I suspect is happenning here is that as a bunch or re-transmissions fail, TCP backs off for longer and longer before re-tranmitting and gets to the point that the time being waited is ridiculously long. What I would like to be able to go, both to test this theory and hopefully solve the problem of it happening, is to reset the backoff timer so it goes back to re-transmitting quickly. Does anyone now if there is way to do this on Linux?
Look in your kernel source directory and then Documentation/networking/ip-sysctl.txt as this covers all of the ip tunables in /proc/sys/net/ipv4. Although I suspect some RFC reading and detective work may be in order to get it all working correctly.
Adam