统计tcp状态链接数

# netstat -n | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}'

  ESTABLISHED 471
  FIN_WAIT1 3
  FIN_WAIT2 52
  SYN_SENT 1
  TIME_WAIT 725

修改tcp链接时间状态值

tcp_keepalive_time = 30 
tcp_keepalive_probes = 9
tcp_keepalive_intvl = 75