Optimal DNS Setup

[Edrick Smith]

So I'm trying to better understand the ideal cPanel DNS scenario.

Lets say for example I have a main infrastructure in Location A where our main cabinet is. A remote site on the other side of the coast (Location B) which is just a dedicated server or two for other uses and I want to add at least a 3rd location over seas.

So in this scenario its possible that the main brunt of sites would be located in A and some alternative services In B, so makes sense to i feel make uses of cPanel DNS Only. Location C would probably just be strictly a DNS Only service over seas.

What makes the most sense for deploying DNS with cPanel?

Should our main location in general be running cPanel webhosting and DNS on one instance, or should we just be running another environment in the same Location A that is specifically just DNS Services? I guess in the case that you have multiple cPanel servers do you also then still run DNS services in conjunction with the hosting or does it just make sense to have one system running DNS at that location?

In the case that we're running DNS Only at Location B and C is there a way to have sites if their respective server is offline re-direct to a generic page hosted by us that indicates the system may be offline? Is that even possible? Is it even recommended (i could see where white labled clients or something wouldn't want their host having a branded "the servers offline" page. But im just wondering how this is handled.

Or is it essentially that the only point of DNS Only is that the other systems will be able to still point the domain naturally to the IP of the one and only server and that the strict benefit to this is just faster resolution to convert domain to IP internally and in the event of an outage, but provides no intelligent method of redirecting sites in the event of their respective server outage?

 

[ffeingol]

A DNS only server is literally that. It provides DNS service and nothing else.

There are a couple of advantages of DNS only servers (and not using your cPanel servers for DNS):

• It makes it easier for your customers, as you only have one set of name servers (and not a set per cPanel server). Then (for example) if you migrate a site for "server a" to "server b", the customer does not have to update name servers.
• it gives you some redundancy if you don't host all of a clients services. If, for example, you host the clients DNS and web, but their mail is at O365 or Google and you have issues with the cPanel server, DNS and they mail stay up. If DNS and cPanel are on the same server and you have issues with that server, mail goes down also, since DNS won't resolve.

I'm sure others will chime in, but those are the two main advantages that I can think of.

 

[cPRex]

I think your last paragraph sums it up - DNSOnly and having multiple nameservers on different networks ensures the DNS for the sites stays online, but doesn't do anything in regards to high availability for the sites themselves.

If you're interested in that, you might want to read and comment on this thread that was recently started by one of our developers to get more details: New Thread - cPanel High Availability Roadmap

 

[Edrick Smith]

So to clarify, the best method would be

Location A)
cPanel Server 1
cPanel Server 2
DNS Only Server A

Location B)
cPanel Server 3
DNS Only Server B

Location C) Over Seas
DNS Only Server C

Then on the main system that say hosts the primary domain that is being used for nameserver A record pointing for example;
On Main server where hostingsite.com is located and
ns1.hostingsite.com - A Record to DNS Server A
ns2.hostingsite.com - A Record to DNS Server B
ns3.hostingsite.com - A Record to DNS Server C

Now where I'm confused is;

Do you just then login to each specific cpanel webhosting server and add the 3 DNS Only Systems on those and then tell it to synchronize changes?

But NOT login on the DNS Only systems and link the DNS Only systems together? Is it basically just the cpanel hosting servers responsibility to send changes to the DNS Only?

So on Server 1, Server 2 and Server 3 at the Site B, I would login to each of those units and add all 3 DNS Only instances to the cluster on that system and synchronize? Or should they all be set to stand alone only


Also in which case is "too many" dns servers in a cluster. IE will it always go "top down" from ns1 to ns2 to ns3 or is it going to somehow intelligently pick between the closet at least internationally. If ns3 is the international location will users in that region theoretically resolve faster via that?

 

[cPRex]

Do you just then login to each specific cpanel webhosting server and add the 3 DNS Only Systems on those and then tell it to synchronize changes?

But NOT login on the DNS Only systems and link the DNS Only systems together? Is it basically just the cpanel hosting servers responsibility to send changes to the DNS Only?

That's exactly correct. Synchronize on the web server, standalone on the DNSOnly machines.

Also in which case is "too many" dns servers in a cluster. IE will it always go "top down" from ns1 to ns2 to ns3 or is it going to somehow intelligently pick between the closet at least internationally. If ns3 is the international location will users in that region theoretically resolve faster via that?

There isn't any type of geographical lookup happening on the cPanel side, so it'll go to whichever one it can at that point in time.