Is your feature request related to a problem? Please describe.
Yes, I have connections behind routers that get their IPv6 address change frequently. Therefore, I have all of them mapped to DDNS FQDNs that update using APIs. I am using the option of --external-ip-map which is fixing the issue of P2P connectivity between all the peers until the IP changes. I attempted to add my FQDN record and map it to the internal IPv6 address (Using ULA ranges.) However that comes back with this error.
Error: xyz.example.com is not a valid input for external-ip-map. it should be an IP string or a network name
Describe the solution you’d like
Is it possible to have netbird support FQDN records for the external IP mapping where I would map xyz.domain.com/fd09:50:1a:1b::1 ? That way the external IP mapping would update if the FQDN gets looked up a short interval (say 900 seconds)?
Describe alternatives you’ve considered
IPv6 NAT 
. I know, I am not about to start WW3 fighting with networking people on why I should never NAT IPv6, but the environment I have can’t run GUA addresses on the entire network.
Additional context
This would make it easier to establish P2P connections for peers with IPv6 support on WAN. My routing peer that is on LAN is using an IPv6 ULA address ( In the range of fc00::/7). Netbird seems to treat those address as publicly routable. Those IPs are being passed to other nodes sitting on the internet with an IPv6 GUA address and that leads to the connection never being P2P.
sudo netbird up --external-ip-map "xyz-v6.example.com/<some-IPv6-ULA-Address>"