• https://www.linuxquestions.org/questions/linux-newbie-8/any-way-to-remove-domain-name-at-end-of-username-when-authenticating-with-ldap-sssd-4175593988/

apt install sssd-ad sssd-tools realmd adcli
realm -v discover sumireko.home.dark-link.info
realm join -v sumireko.home.dark-link.info -U waldemar
pam-auth-update --enable mkhomedir

Testing

getent passwd waldemar@home.dark-link.info

Also install Kerberos

apt install krb5-user
klist