(2.4.20-8smp) No outgoing sockets, ingoing is ok

I have a redhat9.0 box. The server runs a meta-search engine which
connects several engines using aync I/O. The program was intensively
debugged.
Sometimes the server presents a strange behaviour. It accepts new
incoming
connections (opening sockets .. for instance the web server, ssh,
etc),
but it is not able to open any outgoing connections until reboot. If i
wait for a long time (30 minutes or so) it starts to work again. The
active connections such us ssh are kept.

I kept under control /proc/<pid>/fs and non active proccess is running
out of file descriptors (no strange number there).

This happen for different users (noboby, myself, root) and for
different processes... when one stops .. all stop

i tested the system with ab (apache bech) and it is able to handle all
the connections. Quite strange

When this happen the tcpdump filter just few packets.


Any idea on what to monitor or to test ?
Any help will be appreciated, this is making me crazy.

My system:

2.4.20-8smp #1 SMP Thu Mar 13 17:45:54 EST 2003 i686 i686 i386
GNU/Linux
model name : Intel(R) Pentium(R) 4 CPU 2.60GHz
cat /proc/meminfo
total: used: free: shared: buffers: cached:
Mem: 1583661056 337104896 1246556160 0 18034688 163811328

cat /proc/sys/fs/file-max
16384
cat /proc/sys/fs/file-nr
2108 82 8192
cat /proc/sys/net/ipv4/ip_local_port_range
32768 61000

# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core
filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

#
# Aggiunto da AG 11/May.04
#
# Set maximum file and inodes
fs.file-max = 16384
fs.inode-max = 65536