Simple packet capture analysis under Linux

Sometimes there are some problems that need us to catch the packet analysis, when you do not have a professional grasp of the package tool, you can use tcpdump to replace (the general release of the tool itself)

For example, we want to analyze the Eth0 interface and 192.168.7.188 this destination IP address 22 port of the contract situation

Tcpdump-i eth0 DST 192.168.7.188 and Port 22

Tcpdump-i eth0 DST 192.168.7.188 and Port 22
Tcpdump:verbose output suppressed, use-v OR-VV for full protocol decode
Listening on eth0, Link-type EN10MB (Ethernet), capture size 65535 bytes
16:51:55.861670 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 2209699250:2209699442, Ack 582840950, win 24 9, Options [Nop,nop,ts Val 428468844 ECR 517889], length 192
16:51:55.868590 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 192:416, ack 1, Win 249, options [Nop,nop,ts Val 428468851 ECR 517897], length 224
16:51:55.870577 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 416:624, ack 1, Win 249, options [Nop,nop,ts Val 428468853 ECR 517899], length 208
16:51:55.872602 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 624:832, ack 1, Win 249, options [Nop,nop,ts Val 428468855 ECR 517899], length 208
16:51:55.874576 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 832:1040, ack 1, Win 249, options [nop,nop,t S Val 428468857 ECR 517900], length 208
16:51:55.876573 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 1040:1248, ack 1, Win 249, options [Nop,nop, TS Val 428468859 ECR 517900], length 208
16:51:55.878574 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 1248:1456, ack 1, Win 249, options [Nop,nop, TS Val 428468861 ECR 517901], length 208
16:51:55.880574 IP 192.168.7.26.ssh > 192.168.7.188.37540:flags [P.], seq 1456:1664, ack 1, Win 249, options [Nop,nop, TS Val 428468863 ECR 517901], length 208