SSH & Remote Administration

Force a specific SSH identity for every host without the typing

🧩 The Challenge

Managing a pile of different SSH keys for work, personal, and random client servers is a nightmare. I’ve spent way too many mornings mistyping -i paths because I forgot which project uses which key.

💡 The Fix

Use the IdentitiesOnly flag in your config file to stop SSH from trying every single key in your agent and getting you locked out of sensitive boxes. It keeps your authentication clean and predictable.

Host *
IdentitiesOnly yes
IdentityFile ~/.ssh/id_ed25519_work
IdentityFile ~/.ssh/id_rsa_client_x

⚙️ Why It Works

Setting this flag forces the client to ignore whatever is sitting in your ssh-agent and only offer the keys you explicitly define for that specific host block. It saves you from those awkward “Too many authentication failures” errors that kill your connection.

🚀 Pro-Tip: Combine this with HostName and User aliases and you can just type ssh client-box instead of a three-line command.

Linux Tips & Tricks | © ngelinux.com | 11/13/2026