Looks nice. I've written something similar, which just uses curl (and no secret) rather than the DynaDNS-like system you have: http://dhcp.io/ http://dhcp.io/

Looks nice. I've written something similar, which just uses curl (and no secret) rather than the DynaDNS-like system you have: http://dhcp.io/ http://dhcp.io/ You seem to benefit from the use of different record types, and the short TTL (10 seconds? Nice). I benefit from simplicity and IPv6 support, although at a cost of not supporting MX, etc, because I judged the support and abuse potential to be too high.