OPNsense Forum

English Forums => General Discussion => Topic started by: comotion on January 06, 2021, 03:43:29 PM

Title: Single-stack IPv6 and DNS for DHCPv6
Post by: comotion on January 06, 2021, 03:43:29 PM
I've been running dual-stack for a while and it's pretty painful with the duplicate configuration. I'd love to take the plunge into DNS64/NAT64 but one big thing seems to be missing. Biggest problem with IPv6 is that there is no way to discover the addresses of clients, not even when they run DHCPv6. Leases-to-DNS mapping seems to be a DHCPv4-only feature.

Finding internal clients and services is essential, and I can't add all 200+ clients to static mappings, nor require all clients to run multicastDNS.

Anyone have experience with single-stack IP6, or some solution to local name resolution on IPv6?
Title: Re: Single-stack IPv6 and DNS for DHCPv6
Post by: Maurice on January 15, 2021, 01:22:53 AM
The issue is the very limited integration of the DHCPv6 server and Unbound in OPNsense, not a general limitation of DHCPv6.

I run several IPv6-only LANs with OPNsense, but DHCP and DNS are mostly handled by a Windows Server. The Microsoft DHCP server registers dynamic DHCPv6 leases in the Microsoft DNS server just fine.
Microsoft's DNS server doesn't support DNS64 (at least in 2012 R2). So I use OPNsense (Unbound) as the primary DNS resolver. Domain overrides forward local zones to the MS DNS server. This can also be done the other way round (clients query MS DNS which then forwards to OPNsense).

This way, name resolution works fine for most internal clients. (Except Android, which doesn't support DHCPv6 at all.)

Cheers

Maurice