Summary of common SSH commands

Secure Shell The abbreviation is SSH, from IETF Network working group of （Network Working Group） Established by ,SSH It is a security protocol based on application layer and transport layer , For the computer's shell Provide a secure transport and use environment .

It is easy to use

The simplest use is without parameters .

> ssh rumenz.com
[email protected]'s password:

Log in to the host in this form , The current user will be used for login by default . For the first time ,SSH Will confirm the authenticity of the target host , If there is no problem , Input yes that will do .

Specify the user name to log in

Method 1

> ssh -l rumenz rumenz.com

Method 2

> ssh [email protected]

Method 2 is more commonly used

Specify port login

SSH The default port number is 22. Most modern Linux System 22 Ports are all open . If you run ssh Program without specifying a port number , It's directly through 22 The port sends the request .

If we don't want to pass 22 Port login , Then we can use -p Option to specify the port .

> ssh [email protected] -p 1234

modify SSH Default port for

Only need to modify /etc/ssh/ssh_config , Change the following line ：

> vim /etc/ssh/ssh_config
Port 1234

// restart ssh 
> systemctl restart sshd.service

Request compression for all data

Use -C Options , All through SSH Data sent or received will be compressed , And still encrypted .

> ssh -C [email protected]

however , This option is useful when the network speed is not very fast , And when the network speed is fast , Using compression will reduce efficiency , So use it as appropriate .

Turn on debug mode

For some reason , We want to track and debug the SSH Connection .SSH Provided -v This is why the option parameters are set . It can see in which link there is a problem .

> ssh -v [email protected]

OpenSSH_7.9p1, LibreSSL 2.7.3
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 48: Applying options for *
debug1: Connecting to rumenz.com port 22.
debug1: Connection established.
debug1: identity file /Users/mac/.ssh/id_rsa type 0
debug1: identity file /Users/mac/.ssh/id_rsa-cert type -1
debug1: identity file /Users/mac/.ssh/id_dsa type -1
debug1: identity file /Users/mac/.ssh/id_dsa-cert type -1
debug1: identity file /Users/mac/.ssh/id_ecdsa type -1
debug1: identity file /Users/mac/.ssh/id_ecdsa-cert type -1
debug1: identity file /Users/mac/.ssh/id_ed25519 type -1
debug1: identity file /Users/mac/.ssh/id_ed25519-cert type -1
debug1: identity file /Users/mac/.ssh/id_xmss type -1
debug1: identity file /Users/mac/.ssh/id_xmss-cert type -1
...

Bind source address

If a computer or server has multiple network cards , Then there may be more than one ip, You can't tell which one you're using IP Connect to SSH The server . To solve this situation , We can use -b Option to specify a IP Address . This IP Will be used as the source address to establish the connection .

> ssh -b 1.2.3.4 [email protected]

Remote execution command

If we just want to execute a command remotely , You can just follow the command directly

> ssh [email protected] ls -l

Mount remote file system

sshfs It allows you to mount the file system of the remote host directly locally . Its usage format is as follows ：

> sshfs -o idmap=user [email protected]:/home/user ~/Remote

This command can send the remote host pi Mount the user's home directory to the local home directory rumenz Folder .

> sshfs -o idmap=user [email protected]:/home/pi ~/rumenz

Link to the original text :https://rumenz.com/rumenbiji/ssh-common-commands.html

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