TP-Link TD-8816 User Manual page 36

secondary DNS IP to 0.0.0.0. If you want to use DNS relay, you can setup DNS server IP
to 192.168.1.1 on their Computer. If not, the device will perform as no DNS relay.

Primary DNS Server: Type in your preferred DNS server.

Secondary DNS Server: Type in your preferred DNS server.

Radvd Enable: Enable the Radvd if you need.

DHCP6 Server: Enable the DHCP6 server if you need.

Note:
If Use Auto Discovered DNS Server Only is selected in DNS Relay, this modem router will
accept the first received DNS assignment from one of the PPPoA, PPPoE or MER/DHCP enabled
PVC(s) during the connection establishment. If Use User Discovered DNS Server Only is
selected in DNS Relay, it is necessary for you to enter the primary and optional secondary DNS
server IP addresses. After type in the address, click SAVE button to save it and invoke it.
 DHCP Relay: Select Relay, then you will see the next screen (shown in Figure 4-17), the
modem router will work as a DHCP Relay. A DHCP relay is a computer that forwards DHCP
data between computers that request IP addresses and the DHCP server that assigns the
addresses. Each of the device's interfaces can be configured as a DHCP relay. If it is enabled,
the DHCP requests from local PCs will forward to the DHCP server runs on WAN side. To
have this function working properly, please run on Router mode only, disable the DHCP
server on the LAN port, and make sure the routing table has the correct routing entry.

DHCP Server IP for Relay Agent: Enter the DHCP server IP Address runs on WAN
side.

Note:
If you select Disabled, the DHCP function will not take effect.
TD-8816 ADSL2+ Modem Router User Guide
Figure 4-17
29