Hi Ray, I'm not quite sure why you would have your caching servers forward to other DNS servers (Google, OpenDNS, etc). I would enable recursion on them and would not forward anything. I would also consider making these caching servers at each location slave your *internal* authoritative zones (or views) to override recursion.
As you stated, you can keep your AD DNS servers authoritative for your AD domains and point your AD clients directly to these servers. They can be configured to forward to your BIND environment which performs recursion and resolution for non-AD 'internal' domains/views. You can also configure your BIND 'internal' caching servers to slave your AD zones as well. Cheers, Josh -----Original Message----- From: bind-users [mailto:bind-users-boun...@lists.isc.org] On Behalf Of Ray Van Dolson Sent: Tuesday, November 8, 2016 7:10 PM To: bind-users@lists.isc.org Subject: Enterprise DNS Architecture - AD and BIND Greetings; Am reviewing our DNS setup which has organically evolved over the years and most certainly is due for an update: - We have AD servers responsible for our primary domain (internally). - We have other sets of AD servers responsible for other domains in DMZ's and such. - We have a BIND Master/Slave pair acting as a hidden master for external zones as well as doing split view for some of those same zones where we want to return "non-public" IP's for queries that would otherwise be answered with an external address. - We have multiple BIND caching servers. Some at remote sites that handle split duty for Internet resolution (enabling accurate geolocation for Internet based services -- our own included) and internal lookups. In some cases, these "remote" caching servers need to forward lookups to other "super" caching servers which have more privileged access to the authoritative servers listed above... there are about a dozen of these zones. They do static-stub zones for the AD managed zones. Another challenge is when clients point to them directly, Dynamic DNS (RFC2136) doesn't work. Theoretically we could make BIND handle this and forward on to AD, but adds complexity. The caching servers also do RPZ. We're now wanting to add some additional logic to resopnd differently to VPN clients for some of our VoIP technologies to send RTP over the Internet vs. over a VPN tunnel... I'd like to make this all much simpler, avoid mixing roles of servers and help guide us as we decide what servers to deploy where. KISS principle I guess. In an ideal world, I could completely pitch the whole split view thing (where rr.domain.com resolves differently for Internet clients than for "internal" clients). I can't think of a good way to avoid this complexity, however. What I'm thinking: - Have an AD server at every location we have a BIND server. This way client machines talk DNS *only* to AD servers so Dynamic DNS & friends work reliably. AD servers would then forward to BIND servers as needed. + Alternative: Configure clients to do DNS updates via DHCP Option 81, etc. instead of via Dynamic DNS. This would allow clients to point at BIND and take advantage of Anycast for resiliency and I avoid needing to figure out how to make BIND pass RFC 2136 requests on from clients to AD reliably... - Caching Servers will be the same configuration no matter where they are, and do the same things: + "." will forward out to OpenDNS or Google, etc. for Internet lookups. + Will be a "slave" for all AD owned domains. Thought here is better client response times and fewer issues w/ TTL and cache and better resiliency... - Alternative: Leave these as static-stub, but now I made need logic in Ansible or whereever to point to "nearby" AD servers depending on where the BIND server lives to keep response times low when things aren't cached. That or not care about latency... + Will be a "slave" for all of the split-view zones (only for the "internal" view). Could do static-stub here as well, but think slave may serve us better for similar reasons as w/ AD. + I can introduce my split view zones for VPN here as well. I haven't thought this one through fully yet, but am hopeful I don't need to fully duplicate the zones above and could instead forward queries from one view to another........ - Authoritative BIND Servers mostly stay as-is aside from needing to be configured to send notify's out to caching servers and proper FW access maintained for AXFR. Please pick this apart and let me know where I'm going astray. :) Thanks, Ray _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users