Security considerations when updating settings from a remote system

To configure the SSH key authentication, you must place the user's public key on the server in a special directory.When the user connects to the server, the server will ask for proof that the client has the associated private key.This means blocking or restricting access to every port except for those that should be publicly available.On a typical server, a number services may be running by default.If communication channels are not encrypted, attackers can gain valuable information by watching your monitoring information.

A firewall is a piece of software (or hardware) that controls what services are exposed to the network.

However, when password-based logins are allowed, malicious users can repeatedly attempt to access the server.