I am running a Fedora Linux server at a colocation place in Rotterdam The Netherlands. The server runs Plesk 7 has a lot of options and possibilities and all is nice.
Until I found out a strange networking problem, first during FTP-transfers. When I downloaded a lot of small files (around 200 bytes), the connection was lost at 15 seconds + some random time. My FTP client was telling me there was a time-out.
I tried to figure out this problem, and while doing this I have seen that most of the ports used with the FTP transfer were staying in the TIME_WAIT state (I have monitored this with 'netstat -tc' and then started this FTP transfer).
First of all, I was thinking of a badly configured proftpd, but there was nothing to find and a couple of different configurations for proftpd didn't make the situation any better. At that point I found out the same problem exists with the Apache webserver: when many small files (like thumbnails) are loaded, no communication is possible anymore to my server. All ports must be in use, and those are staying in the TIME_WAIT state after a certain time-out (I guess). The problem is that's it very irritating (of course), but also, clients will get time-outs and during the time all ports are in the TIME_WAIT state I can't connect to my server in any way (not even SSH).
Does this problem sound familiar to anybody, does anyone have a good solution for this problem?