Before changing these you should understand what they are doing.
See for example
/usr/share/doc/kernel-doc-2.4.2/networking/ip-sysctl.txt.
or this
online tutorial.
% cat /proc/sys/net/ipv4/ip_local_port_range 32768 61000 [For some reason many systems are now configured to prevent one from using a large number of ports]. [To change this to try to use from port 1025 to 65535] # echo "1025 65535" > /proc/sys/net/ipv4/ip_local_port_range % cat /proc/sys/net/ipv4/tcp_tw_recycle 0 [To change this to on] # echo "1" > /proc/sys/net/ipv4/tcp_tw_recycle % cat /proc/sys/net/ipv4/tcp_max_tw_buckets 180000 % cat /proc/sys/net/ipv4/tcp_fin_timeout 60 [To change this to 3 seconds] # echo "3" > /proc/sys/net/ipv4/tcp_fin_timeout [To have these new values take effect you may have to do (as root)] # /etc/rc.d/init.d/network restart
If you want these new values to survive across reboots you can at them to /etc/sysctl.conf.
# Allowed local port range net.ipv4.ip_local_port_range = 1025 65535 net.ipv4.tcp_tw_recycle = 1 net.ipv4.tcp_fin_timeout = 3