登入遠端伺服器需要指定ssh開放的埠號，一般在購買遠端伺服器上會有顯示：ssh -p埠號 登入賬號名稱（一般是root）@遠端伺服器ip，然後它會提示你輸入密碼

scp命令傳輸檔案時要指定開放的埠號，否則它預設的22埠是拒絕連線的。（錯誤示範）
scp -r /home/lin/Desktop/adslproxy/ [email protected]:/home/download

lin@ubuntu:~/Desktop/git$ scp -r /home/lin/Desktop/adslproxy/ root@xx.xx.xx.xx:/home/download
ssh: connect to host xx.xx.xx.xx port 22
 
: Connection refused
lost connection

scp指定埠號傳輸檔案

scp -r -P埠號 /home/lin/Desktop/adslproxy/ [email protected]xx.xx.xx.xx:/home/download
[email protected]xx.xx.xx.xx's password: 
config.py                                     100%  578     0.6KB/s   00:00    
__init__.py                                   100%  147     0.1KB/s   00
 
:00    
db.cpython-36.pyc                             100% 2622     2.6KB/s   00:00    
config.cpython-36.pyc                         100%  475     0.5KB/s   00:00    
__init__.cpython-36.pyc                       100%  346     0.3KB/s   00:00    
api.cpython-36.pyc                            100% 1505     1.5KB/s   00:00    
sender.cpython-36.pyc                         100% 3019     3.0KB/s   00
 
:00    
sender.py                                     100% 3039     3.0KB/s   00:00    
api.py                                        100% 1508     1.5KB/s   00:00    
db.py                                         100% 1926     1.9KB/s   00:00    

由於預裝系統是centos7.3，防火牆操作命令與linux還是有些區別
1、檢視防火牆服務狀態 systemctl status firewalld

[root@localhost download]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)

2、檢視防火牆執行狀態（是否開啟關閉）firewall-cmd –state

[root@localhost download]# firewall-cmd --state
running

3、關閉防火牆 service firewalld stop

[[email protected] download]# service firewalld stop
Redirecting to /bin/systemctl stop firewalld.service

4、開啟防火牆service firewalld start

[[email protected] download]# service firewalld start
Redirecting to /bin/systemctl start firewalld.service

5、重啟防火牆 service firewalld restart

[root@localhost download]# service firewalld restart
Redirecting to /bin/systemctl restart firewalld.service

6、檢視開放埠 firewall-cmd –list-all

trusted (active)
  target: ACCEPT
  icmp-block-inversion: no
  interfaces: eth0
  sources: 
  services: 
  ports: 8888/tcp   #這裡開放了8888埠
  protocols: 
  masquerade: no
  forward-ports: 
  source-ports: 
  icmp-blocks: 
  rich rules: 

7、開放指定埠[[email protected] download]# firewall-cmd –permanent –add-port=22/tcp 這裡的22是要開放的埠

[[email protected] download]# firewall-cmd --permanent --add-port=22/tcp
success

8、關閉指定埠 firewall-cmd –permanent –remove-port=22/tcp

[[email protected] download]# firewall-cmd --permanent --remove-port=22/tcp
success

9、重啟防火牆（開啟或關閉防火牆後需要重啟才能生效）firewall-cmd –reload

[root@localhost download]# firewall-cmd --reload
success