Yealink SIP-T2 SERIES Administrator's Manual page 781

Parameters
Network->Basic->IPv6 Config->Static IP Address->IPv6 Prefix(0~128)
Phone User Interface:
Menu->Settings->Advanced Settings (default password: admin)
->Network->WAN Port->IPv6->Static IPv6 Client->IPv6 IP Prefix
network.ipv6_internet_port.gateway
Description:
Configures the IPv6 default gateway.
Example:
network.ipv6_internet_port.gateway = 3036:1:1:c3c7:c11c:5447:23a6:255
Note: It works only if the value of the parameter ―network.ip_address_mode‖ is set
to 1 (IPv6) or 2 (IPv4 & IPv6), and "network.ipv6_internet_port.type" is set to 1 (Static
IP Address).If you change this parameter, the IP phone will reboot to make the
change take effect.
Web User Interface:
Network->Basic->IPv6 Config->Static IP Address->Gateway
Phone User Interface:
Menu->Settings->Advanced Settings (default password: admin)
->Network->WAN Port->IPv6->Static IPv6 Client->IPv6 Default Gateway
network.ipv6_primary_dns
Description:
Configures the primary IPv6 DNS server.
Example:
network.ipv6_primary_dns = 3036:1:1:c3c7: c11c:5447:23a6:256
Note: It works only if the value of the parameter "network.ip_address_mode" is set
to 1 (IPv6) or 2 (IPv4 & IPv6). In DHCP environment, you also need to make sure the
value of the parameter "network.ipv6_static_dns_enable" is set to 1 (On). If you
change this parameter, the IP phone will reboot to make the change take effect.
Web User Interface:
Network->Basic->IPv6 Config->Static IP Address->Primary DNS
Phone User Interface:
Menu->Settings->Advanced Settings (default password: admin)
->Network->WAN Port->IPv6->Static IPv6 Client->IPv6 Pri.DNS
Or Menu->Settings->Advanced Settings (default password: admin)
->Network->WAN Port->IPv6->DHCP IPv6 Client->Staic DNS(Enabled) ->IPv6
Configuring Advanced Features
Permitted Values
IPv6 address
IPv6 address
Default
Blank
Blank
759