- OpenSSH Config File Examples (cyberciti.biz)
- ssh_config (linux.die.net)
- man-ssh
SSH CHEAT SHEET
This quick reference cheat sheet provides various for using SSH.
protocolremotenetwork22
4
Sections
19
Cards
#Getting Started
Connecting
Connect to a server (default port 22)
$ ssh [email protected]
Connect on a specific port
$ ssh [email protected] -p 6222
Connect via pem file (0400 permissions)
$ ssh -i /path/file.pem [email protected]
See: SSH Permissions
Executing
Executes remote command
$ ssh [email protected] 'ls -l'
Invoke a local script
$ ssh [email protected] bash < script.sh
Compresses and downloads from a server
$ ssh [email protected] "tar cvzf - ~/source" > output.tgz
SCP
Copies from remote to local
$ scp user@server:/dir/file.ext dest/
Copies between two servers
$ scp user@server:/file user@server:/dir
Copies from local to remote
$ scp dest/file.ext user@server:/dir
Copies a whole folder
$ scp -r user@server:/dir dest/
Copies all files from a folder
$ scp user@server:/dir/* dest/
Copies from a server folder to the current folder
$ scp user@server:/dir/* .
Config location
| File Path | Description |
|---|---|
/etc/ssh/ssh_config | System-wide config |
~/.ssh/config | User-specific config |
~/.ssh/id_{type} | Private key |
~/.ssh/id_{type}.pub | Public key |
~/.ssh/known_hosts | Known Servers |
~/.ssh/authorized_keys | Authorized login key |
SCP Options
| Options | Description |
|---|---|
scp -r | |
scp -C | |
scp -v | Prints |
scp -P 8080 | Uses a specific |
scp -B | |
scp -p |
Config sample
Host server1
HostName 192.168.1.5
User root
Port 22
IdentityFile ~/.ssh/server1.key
Launch by alias
$ ssh server1
See: Full Config Options
ProxyJump
$ ssh -J proxy_host1 remote_host2
$ ssh -J user@proxy_host1 user@remote_host2
Multiple jumps
$ ssh -J user@proxy_host1:port1,user@proxy_host2:port2 user@remote_host3
ssh-copy-id
$ ssh-copy-id user@server
Copy to alias server
$ ssh-copy-id server1
Copy specific key
$ ssh-copy-id -i ~/.ssh/id_rsa.pub user@server
#SSH keygen
ssh-keygen
$ ssh-keygen -t rsa -b 4096 -C "[email protected]"
| - | - | - |
|---|---|---|
-t | Type of key | |
-b | The number of bits in the key | |
-C | Provides a new comment |
{.left-text}
Generate an RSA 4096 bit key with email as a comment
Generate
Generate a key interactively
$ ssh-keygen
Specify filename
$ ssh-keygen -f ~/.ssh/filename
Generate public key from private key
$ ssh-keygen -y -f private.key > public.pub
Change comment
$ ssh-keygen -c -f ~/.ssh/id_rsa
Change private key passphrase
$ ssh-keygen -p -f ~/.ssh/id_rsa
Key type
- rsa
- ed25519
- dsa
- ecdsa
known_hosts
Search from known_hosts
$ ssh-keygen -F <ip/hostname>
Remove from known_hosts
$ ssh-keygen -R <ip/hostname>
Key format
- PEM
- PKCS8
#SSH Tunneling
SSH Tunnel Options
| Option | Description |
|---|---|
-L | Local port forwarding |
-R | Remote port forwarding |
-D | Dynamic port forwarding |
-f | Run in background |
-N | Do not execute a remote command |
-g | Allow remote hosts to connect to local forwarded ports |
{.left-text}
more details on flag above with man ssh
Local Port Forwarding
# Forward a local port to a remote server
ssh -L local_port:remote_host:remote_port user@ssh_server
# Example: Forward local port 8080 to remote port 80 on example.com
ssh -L 8080:example.com:80 user@ssh_server
Dynamic Port Forwarding
# Create a SOCKS proxy on a local port
ssh -D local_port user@ssh_server
# Create a SOCKS proxy on local port 1080 in the background
ssh -f -N -D 1080 user@ssh_server
Background Tunnel
# Create a local port forwarding tunnel in the background
ssh -f -N -L local_port:remote_host:remote_port user@ssh_server
Multiple Tunnels
# Create multiple tunnels in a single SSH command
ssh -L 8080:example.com:80 -L 3306:db.example.com:3306 user@ssh_server
Combining Options
# In background, no command, allow remote host, local port forward, identity_file
ssh -f -N -g -L 8080:example.com:80 -i ~/.ssh/custom_key user@ssh_server