Fixing SSH 'Too Many Authentication Failures' With Multiplexing and Config Tweaks

A common SSH problem, 'Too many authentication failures,' often stems from the client's own configuration rather than the server. Connection multiplexing via ControlMaster can cause socket collisions when chaining ProxyJump hosts, which is avoided by giving each hop a distinct ControlPath. Loading several keys into ssh-agent can also trigger the error, since the server may reject attempts before the correct key is tried; IdentitiesOnly with explicit IdentityFile ordering resolves this. Because SSH applies the first matching value for each option, a broad Host * block placed early can silently override more specific host settings, so catch-all defaults belong at the end or in separately included files.