1 查看TCP连接状态
netstat -n|awk '{print $6}'|sort|uniq -c|sort -rn
netstat -n|awk '/^tcp/ {++S[$NF]};END{for(a in S)print a,S[a]}'
netstat -n|awk '/^tcp/ {++state[$NF]};END{for(key in state)print key," ",state[key]}'
netstat -n|awk '/^tcp/ {++arr[$NF]};END{for(k in arr)print k," ",arr[k]}'
netstat -n|awk '/^tcp/ {print $NF}'|sort|uniq -c|sort -rn
netstat -ant|awk '{print $NF}'|grep -v '[a-z]'|sort|uniq -c
2 查找请求数排前20的IP
netstat -anlp|grep 80|grep tcp|awk '{print $5}'|awk -F: '{print $1}'|sort|uniq -c|sort -nr|head -n20
netstat -ant|awk '/:80/ {split($5,ip,":");++A[ip[1]]}END{for(i in A)print A[i],i}'|sort -rn|head -n20
3 tcpdump嗅探80端口的访问看看谁最高
tcpdump -i eth0 -tnn dst port 80 -c 100|awk -F"." '{print $1"."$2"."$3"."$4}'|sort|uniq -c|sort -rn|head -n20
4 查找较多time_wait连接
netstat -n|grep TIME_WAIT|awk '{print $5}'|sort|uniq -c|sort -rn|head -n20
5 查找较多的SYN连接
netstat -n|grep SYN|awk '{print $5}'|awk -F: '{print $1}'|sort|uniq -c|sort -rn|more
6 根据端口列进程
netstat -ntlp|grep 80|awk '{print $7}'|cut -d/ -f1
7查看PHP-cgi进程占用内存总数
total=0;for i in `ps -C php-fpm -o rss=`;do total=$(($total+$i));done;echo "PHP-CGI Memory usage: $total kb"