Linux: Kill Orphaned Socket FIN_WAIT1

tcp_orphan_retries setting controls how many attempts will be done before a server-less port is released. By default, it is 0, to kill the Orphaned Socket, set 1 in tcp_orphan_retries.

# cd /proc/sys/net/ipv4
# echo 1 > tcp_orphan_retries
# netstat -p |grep FIN_WAIT

if all the orphaned socket is gone, restore tcp_orphan_retries

# echo 0 > tcp_orphan_retries