经过两天的不屑努力打成的包，亲测可用。 usage: java Tcpdump 0 :en0 data link:EN10MB(Ethernet) address:/fe80:0:0:0:1498:2841:ccb7:b43d /ffff:ffff:ffff:ffff:0:0:0:0 null address:/192.168.1.113 /255.255.255.0 /192.168.1.255