Authentication via iPXE when using boot, chain, kernel, initrd etc.

[NiKiZe]

The most standard is basic http authentiocation as described above and on the iPXE login page,
Actual implementation on the server depends on what you are running there, but a search for ".htaccess password" would show how to set up apache for these kind of things, but there is many other ways as well.

annother option is to use iPXEs params and do a normal http POST to a webserver with a script that does the authentication.