Auths and authz on Linux.
Users in /etc/passwd can authenticate. For LDAP-users:
+username
@netgroup
/etc/security/access.conf/etc/security/access.d/<name>.conf
+: <subject> [subject...] : <source> [source...]
Where subject is a username or netgroup:
username@netgroup
And subject is a network location:
ALLLOCAL129.240.0.0/162001:700:100::/40