10 SSH Config Tricks Every Developer Should Know

The ~/.ssh/config file is the most underused tool in a developer's toolkit. Most people type out full SSH commands every time. Once you learn these tricks, you'll never go back.

1. Basic Host Aliases

Stop typing ssh -i ~/.ssh/key user@192.168.1.50 -p 2222. Add this to your config:

Host myserver
  HostName 192.168.1.50
  User deploy
  Port 2222
  IdentityFile ~/.ssh/deploy_key

Now just type ssh myserver. This also works with scp, sftp, and rsync.

2. Wildcard Defaults

Set defaults for all connections:

Host *
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519
  ServerAliveInterval 60
  ServerAliveCountMax 3

This keeps connections alive, adds keys to the agent automatically, and stores passphrases in macOS Keychain.

3. Jump Hosts (ProxyJump)

Access servers behind a bastion/jump host in one command:

Host bastion
  HostName bastion.company.com
  User admin

Host internal-db
  HostName 10.0.1.20
  User dbadmin
  ProxyJump bastion

Now ssh internal-db automatically jumps through the bastion. No more ssh -J flags.

4. Port Forwarding Made Permanent

Instead of remembering -L flags:

Host dev-server
  HostName dev.company.com
  User dev
  LocalForward 3000 localhost:3000
  LocalForward 5432 localhost:5432
  LocalForward 6379 localhost:6379

Every time you ssh dev-server, your local ports automatically forward to the remote services.

5. Agent Forwarding

Use your local SSH keys on the remote server (e.g., for git operations):

Host dev
  HostName dev.company.com
  ForwardAgent yes

Now you can git pull on the remote server using your local GitHub key. Warning: only enable this for servers you trust.

6. Different Keys for Different Services

Host github.com
  IdentityFile ~/.ssh/github_ed25519

Host gitlab.company.com
  IdentityFile ~/.ssh/work_ed25519

Host *.internal.company.com
  IdentityFile ~/.ssh/work_ed25519
  User admin

Wildcards (*) let you apply settings to multiple hosts at once.

7. Keep Connections Alive

Tired of "broken pipe" disconnections?

Host *
  ServerAliveInterval 60
  ServerAliveCountMax 3
  TCPKeepAlive yes

This sends a keepalive packet every 60 seconds and disconnects only after 3 missed responses.

8. Connection Multiplexing

Reuse a single SSH connection for multiple sessions:

Host *
  ControlMaster auto
  ControlPath ~/.ssh/sockets/%r@%h-%p
  ControlPersist 600

Create the socket directory first: mkdir -p ~/.ssh/sockets

The first connection authenticates normally. Every subsequent connection to the same host reuses it — instant connections with zero auth overhead.

9. Compression for Slow Networks

Host slow-server
  HostName server.faraway.com
  Compression yes

Enables compression on the SSH tunnel. Makes a noticeable difference on high-latency or low-bandwidth connections.

10. Custom Commands on Connect

Run a command immediately after connecting:

Host dev
  HostName dev.company.com
  RemoteCommand cd /var/www/app && exec $SHELL -l
  RequestTTY yes

This drops you directly into your project directory every time.

Bonus: Organize Your Config

As your config grows, keep it organized with comments:

# ── Defaults ──
Host *
  AddKeysToAgent yes
  UseKeychain yes
  ServerAliveInterval 60

# ── Work ──
Host bastion
  HostName bastion.company.com

# ── Personal ──
Host homelab
  HostName 192.168.1.10

Or split it into multiple files using Include:

Include ~/.ssh/config.d/*

Managing All This Visually

If you have dozens of servers, managing a text config file gets unwieldy. Tools like Pluto Door let you manage connections through a visual interface while still respecting your SSH config — so you get the convenience of a GUI with the power of your config file.

The config file is your multiplier. Spend 30 minutes setting it up, save hours every month.