1,查看apache进程:

ps aux | grep httpd | grep -v grep | wc -l

2,查看80端口的tcp连接:

netstat -tan | grep "ESTABLISHED" | grep ":80" | wc -l

3,通过日志查看当天ip连接数，过滤重复:

cat access_log | grep "20/Oct/2008" | awk '{print $2}' | sort | uniq -c | sort -nr

4,当天ip连接数最高的ip都在干些什么(原来是蜘蛛):

cat access_log | grep "20/Oct/2008:00" | grep "122.102.7.212" | awk '{print $8}' | sort | uniq -c | sort -nr | head -n 10

5,当天访问页面排前10的url:

cat access_log | grep "20/Oct/2008:00" | awk '{print $8}' | sort | uniq -c | sort -nr | head -n 10

6,用tcpdump嗅探80端口的访问看看谁最高

tcpdump -i eth0 -tnn dst port 80 -c 1000 | awk -F"." '{print $1"."$2"."$3"."$4}' | sort | uniq -c | sort -nr

接着从日志里查看该ip在干嘛:
cat access_log | grep 122.102.7.212| awk '{print $1"\t"$8}' | sort | uniq -c | sort -nr | less
 
   
7,查看某一时间段的ip连接数:
 
   
grep "2006:0[7-8]" www20060723.log | awk '{print $2}' | sort | uniq -c| sort -nr
 
   
几个应付DOS***的管理脚本 
 
   
关键字: dos 
 
   
$ cat dos_ip.sh 
 
   
#!/bin/bash
 netstat -an|grep SYN_RECV|awk -F' ' '{print $5;}'|awk -F':' '{print $1;}'|sort| uniq -c | sort -nr | head -n $1 
 
   
  
 
   
$ cat dos_attack.sh
 #!/bin/bash 
 
   
netstat -an|grep SYN_RECV|awk -F' ' '{print $5;}'|awk -F':' '{print $1;}'|sort| uniq -c | sort -nr | head -n $1|awk -F' ' '{print $2}'|xargs --replace=TTT /sbin/iptables -t filter -I INPUT 1 -m state --state NEW -m tcp -p tcp -s TTT --dport 80 -j REJECT --reject-with icmp-host-prohibited 
 
   
  
 
   
$ cat nst.sh 
 
   
#!/bin/bash 
 
   
if [[ "1" != "1$1" ]]; then
     netstat -an|grep $1|awk -F' ' '{print $5;}'|awk -F':' '{print $1;}'|sort| uniq -c | sort -nr | head -n 10
 else
     netstat -an|awk -F' ' '{print $5;}'|awk -F':' '{print $1;}'|sort| uniq -c | sort -nr | head -n 10
 fi