# [solved] connection stops at "dup ack"

## balrok2

hello, since 3 days i have a weird problem:

in short: my connection to my server stops after some time, and it's more possible that the connection stops, if more data is send

but: it seems that it's not my server, i tested everything with windows (on the same pc - so it's not the hardware) and with gentoo from another pc.. and there doesn't occur any problem

describing my computers:

gentoo-desktop <-lan-> gentoo-server <-wlan-> router_to_internet

the gentoo-server is something like a firewall/webserver/working-space for me, it also routes the internet to my desktop

the internet routing works perfect (at least i haven't noticed that anything changed)

also i could play an online game without any lost connections

the routing is done through iptables

but from my desktop to the server i noticed connection-aborts (but i would say "stops" cause it seems, that after the connection is lost, nothing will be send anymore)

this happens when i run a irc-client on my server and connect to it over ssh, but that the connection stops happens only very seldom, but i can speed the stopping-process up by redrawing the screen and keep the terminal in full size

when i do cat /var/log/apache2/access_log on the server with ssh my connection i can be 100% sure that connection stops in maximum 1 second

when i open a html-file on the server it displays nothing to me

when i try to connect with a game client to my server, the connection is also lost after some time..

i took wireshark to show you what happens at last, when i break a connection with "cat apache2/access_log"

http://www.bilder-upload.eu/show.php?file=iNbgJy0Tm02kr1b.png

if you want any other informations about my computer please ask..

edit: not the whole connection to the server stops, just the particular ssh/http... connection.. (maybe this wasn't clear through my writing)Last edited by balrok2 on Mon Nov 17, 2008 9:54 pm; edited 1 time in total

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## kallamej

Check whether http://www.snailbook.com/faq/mtu-mismatch.auto.html helps.

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## balrok2

wow - very big thanks  :Smile: 

at least the 

ifconfig eth1 mtu 576

solved my problem, now i read why my network card doesn't like me  :Sad: 

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