After authentication of the first host of a subscriber session, primary, secondary, and extended DNSv4 and DNSv6 name servers and primary and secondary NBNS name servers of the highest authentication origin priority are associated with the subscriber session. The name servers of the authenticating host's IP stack are sent to the client. The same happens when a new host is associated with an existing session and re-authentication is performed.
When a new host is associated with an existing session and no re-authentication is performed, the name servers of the new host's IP stack that are associated with the subscriber sessions are sent to the client. In the case of DHCP relay, the name servers obtained from the DHCP servers are used if a corresponding name server obtained from a higher priority authentication origin is not associated with the session. Also when the DHCP server does not provide name servers, the configured subscriber interface defaults are associated with the session.