linux网络抓包

tcpdump 的抓包保存到文件的命令参数是-w xxx.cap

抓eth1的包 
tcpdump -i eth1 -w /tmp/xxx.cap 

抓 192.168.1.123的包 
tcpdump -i eth1 host 192.168.1.123 -w /tmp/xxx.cap 

抓192.168.1.123的80端口的包 
tcpdump -i eth1 host 192.168.1.123 and port 80 -w /tmp/xxx.cap 

抓192.168.1.123的icmp的包 
tcpdump -i eth1 host 192.168.1.123 and icmp -w /tmp/xxx.cap 

抓192.168.1.123的80端口和110和25以外的其他端口的包 
tcpdump -i eth1 host 192.168.1.123 and ! port 80 and ! port 25 and ! port 110 -w /tmp/xxx.cap 

抓vlan 1的包 
tcpdump -i eth1 port 80 and vlan 1 -w /tmp/xxx.cap 

抓pppoe的密码 
tcpdump -i eth1 pppoes -w /tmp/xxx.cap 



以100m大小分割保存文件， 超过100m另开一个文件 -C 100m 

抓10000个包后退出 -c 10000 


后台抓包， 控制台退出也不会影响： 
nohup tcpdump -i eth1 port 110 -w /tmp/xxx.cap &