tcpdump -i any port 30002 and host 10.136.242.200 -X # 接口不限，指定端口和ip，进行抓包
tcpdump -i any port 27371 and host 125.7.6.51 -w aa.cap # 将抓包输出写入到aa.cap文件
tcpdump -i vEth0 # 指定接口为vEth0抓包
file aa.cap
aa.cap: pcap capture file, microsecond ts (little-endian) - version 2.4 (Ethernet, capture length 262144)