SSH Cheatsheet

SSH Cheat Sheet

5 Main SSH Commands

1. Connect to Remote Host

ssh user@hostname
ssh -p 2222 user@hostname

• Establishes an interactive shell session on the remote host
• -p specifies a custom port (default is 22)

2. Generate SSH Keys

ssh-keygen -t ed25519 -C "your_email@example.com"
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

• Creates public/private key pairs for passwordless authentication
• ed25519 is recommended for new keys (more secure, faster)

3. Copy SSH Keys to Remote Host

ssh-copy-id user@hostname

• Installs your public key on the remote host for passwordless login
• Alternative: cat ~/.ssh/id_ed25519.pub | ssh user@hostname 'cat >> ~/.ssh/authorized_keys'

4. Copy Files (SCP)

# From remote to local
scp user@hostname:/remote/path/file.txt ./

# From local to remote
scp ./file.txt user@hostname:/remote/path/

# Recursive copy of directories
scp -r ./localdir user@hostname:/remote/path/

• Secure copy protocol for transferring files

5. Interactive File Transfer (SFTP)

sftp user@hostname

• Interactive file transfer session with commands like get, put, ls, cd

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SSH Port Forwarding

Local Port Forwarding (Access remote services locally)

ssh -L local_port:remote_host:remote_port user@ssh_host

Example: Access RDP through jump host

ssh -L 3389:10.10.202.4:3389 pfeddersheim

• Local port 3389 on your machine forwards to 10.10.202.4:3389 via pfeddersheim
• Connect to localhost:3389 on your local machine

Dynamic Port Forwarding (SSH SOCKS proxy)

ssh -D 1080 user@ssh_host

• Creates a SOCKS proxy on local port 1080
• Useful for routing all traffic through the SSH host

Remote Port Forwarding (Expose local services remotely)

ssh -R remote_port:localhost:local_port user@ssh_host

• Forwards remote_port on the SSH host to local_port on your local machine

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Useful SSH Options

Flag	Description
-N	No remote command execution (used with port forwarding)
-f	Run in background after authentication
-T	Disable pseudo-terminal allocation
-v	Verbose mode (debugging)
-vvv	Maximum verbose mode
-i identity_file	Specify private key file
-A	Enable agent forwarding
-X	Enable X11 forwarding
-L	Local port forwarding
-R	Remote port forwarding
-D	Dynamic port forwarding (SOCKS proxy)

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Common SSH Configurations

Edit or create ~/.ssh/config:

Host jump
    HostName pfeddersheim
    User your_username
    Port 22

Host target
    HostName 10.10.202.4
    User your_username
    ProxyJump jump
    LocalForward 3389 10.10.202.4:3389

Then connect with: ssh target