Network Tunning in Linux

# Kernel tuning settings for CentOS5

net.core.netdev_max_backlog=30000
net.ipv4.tcp_max_tw_buckets=2000000
# Bump up send/receive buffer sizes
net.core.rmem_default=262141
net.core.wmem_default=262141
net.core.rmem_max=262141
net.core.wmem_max=262141
net.ipv4.tcp_sack=0

net.ipv4.tcp_dsack=0
net.ipv4.tcp_retries2=5
net.ipv4.tcp_fin_timeout=60
net.ipv4.tcp_keepalive_time=120
net.ipv4.tcp_keepalive_intvl=30
net.ipv4.tcp_keepalive_probes=3
net.core.somaxconn=256

net.core.optmem_max=20480
use netstat -s to determine the best usuage of your network