Feature Request: Allow custom IPv6 source for AAAA records

[ctempleton3]

Description

Feature Request: Allow custom IPv6 source for AAAA records

Summary

ddns-route53 currently derives both IPv4 (A) and IPv6 (AAAA) from WAN detection. This works for IPv4, but not for IPv6 in dual-stack environments where services are hosted on LAN devices.

Problem

In IPv6 networks:

• Each host has its own globally routable IPv6 address
• There is no NAT/port forwarding model like IPv4

The container updates AAAA records using the router’s WAN IPv6, but services are hosted on a different device with its own IPv6. As a result, AAAA records point to the wrong endpoint.

Expected Behavior

Allow AAAA records to use a different source than WAN detection (e.g., a specific host on the LAN).

Proposed Options

Any of the following would solve this:

1. Command-based source

DDNSR53_IPV6_SOURCE=cmd
DDNSR53_IPV6_CMD="ip -6 addr show <interface> | ..."

2. DNS lookup source

DDNSR53_IPV6_SOURCE=lookup
DDNSR53_IPV6_HOST=<hostname>
DDNSR53_IPV6_RESOLVER=<dns-server>

3. Explicit override

DDNSR53_IPV6=<ipv6-address>

Current Workaround

• Use ddns-route53 for A records only
• Maintain AAAA records separately (e.g., script on target host)

Why this matters

IPv6 removes the “single public IP” assumption. DDNS clients need a way to target specific hosts rather than only the router’s WAN address.

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Happy to help test or provide additional details if needed.