前言

Life is tough, but Wireshark makes it easy.
Wireshark 3.6.6是开源软件抓包分析器

一、下载

下载链接：

https://www.wireshark.org/download.html

二、内容

2.1. 路由查看

root@ubuntu:~$ route 
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         _gateway        0.0.0.0         UG    100    0        0 ens33
link-local      0.0.0.0         255.255.0.0     U     1000   0        0 ens33
172.29.2.0      0.0.0.0         255.255.255.0   U     100    0        0 ens33

root@ubuntu:~$ route | grep default
default         _gateway        0.0.0.0         UG    100    0        0 ens33

root@ubuntu:~$ 
heat@ubuntu:~$ route | egrep "Dest|29.2"
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
172.29.2.0      0.0.0.0         255.255.255.0   U     100    0        0 ens33

root@ubuntu:~$ 
root@ubuntu:~$ netstat -rn
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         172.29.2.1      0.0.0.0         UG        0 0          0 ens33
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 ens33
172.29.2.0      0.0.0.0         255.255.255.0   U         0 0          0 ens33

heat@ubuntu:~$

2.2 tcpdump -s

使用tcpdump抓包，抓每个包的前80字节。

root@ubuntu:~# tcpdump -i ens33 -s 80
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens33, link-type EN10MB (Ethernet), capture size 80 bytes
10:53:10.923851 IP 172.29.2.34.53267 > 110.88.208.90.6672: Flags [P.], seq 3104480101:3104480290, ack 450823188, win 1026, length 189
10:53:10.924092 IP 172.29.2.34.53267 > 110.88.208.90.6672: Flags [P.], seq 189:209, ack 1, win 1026, length 20

2.2 tcpdump host x.x.x.x

使用tcpdump抓包，抓与IP地址是x.x.x.x相关的包。

root@ubuntu:~# tcpdump -i ens33 host 172.29.2.34
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens33, link-type EN10MB (Ethernet), capture size 262144 bytes
10:56:18.302908 IP 110.88.208.65.7070 > 172.29.2.34.54070: Flags [.], ack 1582627552, win 509, length 0
10:56:18.415437 IP dl1.wireshark.net.https > 172.29.2.34.54305: Flags [.], seq 3533998645:3534001565, ack 24425167, win 501, length 2920