LimboDNS: Cannot run as hidden primary DNS nor use forwarders?
in...@haul.de
I am trying to use LimboDNS in an (I think) fairly common scenario:
I have a virtual server running on the Internet, with a fixed IP, domain, and everything. I want to run LimboDNS on that one.
For my home network (dynamic IP), I'd like to set up dynamic DNS as a subdomain of my domain. This will enable me to get SSL certificates from LetsEncrypt for my home boxes, i.e. the router and a Raspberry Pi doing various interesting things. The Pi would be the client and regularly update the LimboDNS server with its external IPv4 and IPv6 addresses.
To this end, LimboDNS needs to support one of these scenarios:
a) LimboDNS can use forwarders (so it can handle all DNS requests on my main server)
b) LimboDNS acts as master, supporting domain transfer (AXFR) for the subdomain. Then I'd run bind9 on the server to do all the other stuff, including acting as a slave server for the subdomain, which it will pull from LimboDNS as needed.
c) Same as b above, but bind9 configures the subdomain just as forwarder. To this end, LimboDNS would need a config option to listen only on specific addresses (like 10.1.1.1) rather than "Any". This way, LimboDNS could listen on the server's public address and bind could listen on a provate address (just for the local resolver).
I tried all of these options and came up empty.
Using option a, my server can not resolve any domains except the subdomain hosted by LimboDNS.
Using option b, bind gets "not implemented" when trying the zone transfer.
Option c does not work because LimboDNS hogs port 53 on all IP addresses.
Any ideas how I can achieve this?