SSH Commands & ~/.ssh/config Cheat Sheet — Keys & Port Forwarding

Reference for generating Ed25519 keys, configuring shortcuts in ~/.ssh/config, copying public keys, and local/remote port forwarding tunnels.

Key Generation & Authentication

ssh-keygen -t ed25519 -C "you@example.com"

Generate modern, secure Ed25519 cryptographic key pair

ssh-copy-id -i ~/.ssh/id_ed25519.pub user@server.com

Copy your public key to remote server ~/.ssh/authorized_keys file

chmod 700 ~/.ssh && chmod 600 ~/.ssh/id_*

Set mandatory strict Linux permissions on private SSH keys

Host prod
  HostName 192.168.1.50
  User ubuntu
  IdentityFile ~/.ssh/prod_key

Config shortcut enabling connection with simple command: ssh prod

ssh -L 5432:localhost:5432 user@server.com

Forward local port 5432 to access private remote database through SSH tunnel

ProxyJump bastion.example.com

Route SSH traffic through a secure intermediate bastion/jump host