（1）报文抓取
tcpdump -i eno5 host 10.8.12.154 -w /test.cap-i：抓取的网卡
host：目的地址
-w：生成的文件存放路径
Ctrl+c 结束抓包，抓取的报文存放在/的test.cap下
（2）报文获取
方法1：使用scp命令，将当前设备上/root下的set_fxs_port.cap文件传输到IP为10.8.12.90设备/mnt/hfs1目录下
[root@genewDB ~]# ll
total 20
-rw-r--r-- 1 tcpdump tcpdump 24 Sep 7 08:17 B1205F.pcap
drwxr-xr-x 2 root root 6 May 6 22:19 Desktop
drwxr-xr-x 2 root root 6 May 6 22:19 Documents
drwxr-xr-x 2 root root 6 May 6 22:19 Downloads
drwxr-xr-x 2 root root 6 May 6 22:19 Music
drwxrwxr-x 3 root root 19 Aug 9 11:38 Netman4000
drwxr-xr-x. 3 root root 17 May 4 08:50 Orgin_file
drwxr-xr-x 2 root root 6 May 6 22:19 Pictures
drwxr-xr-x 2 root root 6 May 6 22:19 Public
-rw-r--r-- 1 tcpdump tcpdump 1501 Sep 11 06:07 set_fxs_port.cap
-rw-r--r-- 1 tcpdump tcpdump 512 Sep 11 06:03 set+fxs_port.cap
drwxr-xr-x 2 root root 6 May 6 22:19 Templates
-rw-r--r-- 1 tcpdump tcpdump 7167 Aug 17 18:15 tongji.cap
drwxr-xr-x 2 root root 6 May 6 22:19 Videos
[root@genewDB ~]# pwd
/root
[root@genewDB ~]# scp /root/set_fxs_port.cap root@10.8.12.90:/mnt/hfs1/set_fxs_port.cap
root@10.8.12.90's password:
set_fxs_port.cap 100% 1501 1.5KB/s 00:00方法2：使用SSH Secure File Transfer Client下载到本地；