sshknownhosts

The SSH known_hosts file is a critical component of the Secure Shell (SSH) protocol, used for securely connecting to remote servers. It is a plain text file that stores the public keys of remote hosts that the user has previously connected to. This file is typically located in the .ssh directory within a user's home directory, and its name is known_hosts.

When a user attempts to connect to a remote server using SSH, the client checks the server's public key against the entries in the known_hosts file. If the key matches, the connection is established. If the key does not match, the client warns the user that the server's identity has changed, which could indicate a potential security risk. This warning is crucial for maintaining the security of SSH connections.

The known_hosts file can be manually edited to add or remove entries. However, it is generally recommended to use the ssh-keygen command to manage this file, as it provides a more secure and user-friendly way to handle public keys.

The known_hosts file is an essential part of the SSH protocol, providing a way to verify the identity of remote servers and ensuring the security of SSH connections. It is a simple yet powerful tool that plays a vital role in the secure communication between clients and servers.