To answer your question:
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That one should not be the issue. How many file descriptor you machine
enable you right now:
% unlimit -l
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I get the following results when invoking the command:
C:\Users\strudeau>netsh int ipv4 show dynamicport tcp
Protocol tcp Dynamic Port Range
---------------------------------
Start Port : 49152
Number of Ports : 16384
From the looks of it, I don't lack any ports on my Vista machine. On an
XP machine, on the other hands, trying to open 5000 connections with the
default settings enabled might be a bit problematic since the default
port range is from 1025 through 5000.
Simon