A group interface configured as DHCPv6 Relay or DHCPv6 Proxy only inserts a DNS Recursive Name Server Option (23) in the DHCP Advertise and DHCP Reply message when requested by the DHCPv6 client in the Option Request Option (6) and at least one DNS name server IP address is received during authentication.
An SR OS DHCPv6 server (DHCPv6 relay) and a DHCPv6 proxy server insert the DNS Recursive Name Server Option as a global DHCPv6 option.