RFC 2136 client
Enable >
Interface to monitor
Hostname
TTL seconds
Key name
This must match the setting on the DNS server.
Key type > Zone   > Host   > User
Key
Paste an HMAC-MD5 key here.
Server
Protocol > Use TCP instead of UDP
Description
 
  Note:
You must configure a DNS server in System: General setup or allow the DNS server list to be overridden by DHCP/PPP on WAN for dynamic DNS updates to work.