CDN DNS DNS Expert Advice please :-)

Hi there

I am moderatley comfortable with DNS - however, I am setting up a new server on vultr and would appreciate some expert help with deciding the best way to configure Primary / Secondary DNS delegation.

The end result: I am wanting to achieve is the following:

A primary domain (myhostingco.com) that points to my server instance. Then, point all customer domains to my primary domain nameservers (vanity nameserver) e.g. ns1.myhostingco.com - that in turn then resolve to the server.

In other words - how best to achieve this scenario:

1) myhostingco.com points to my server
2) a new customer wants hosting and when I update their domain DNS to point to myhostingco.com - the changes take place globally in less than 15 minutes.

This setup I hope, will make it easier to manage any future server or IP change, because I can simply update the Primary domain to point to the new server - and all of the client domains will simply follow.

So - how to best utilise some kind of CDN / AnyCast system, so that whenever I change a customer domain DNS - it will very quickly propagate the change for that domain to the Primary domain nameserver.

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I am aware of CloudFlare, DNSME, BUDDYNS, Hurricane Electric etc.... but I'm not exactly sure which route to take / steps to take to achieve this, and would be grateful to receive your advice.

Fortunately, this is a dev server (at the moment) and I have several test domains, so I can practice and nail this without affecting RW sites.

Thank you

 

thanks @eva2000

How do you propose I achieve the desired set up when using Cloudflare?

Like this?

1) point myhostingco.com to Cloudflare
2) set up cloudflare to point to my server IP
3) where to point client domain e.g. myclient.com.au ? Do I just point to ns1.myhostingco.com
Or do I have to set up each client domain to point to cloudflare?

I'm new to cloudflare / anycast so I am not entirely sure what's the best way to achieve this.

 

Thanks for your comment.

Disappointing though! I don't think that will work if there are dozens of client domains.

That's why I prefer a single primary domain change that I can then change that "master" dns and have all the client domains updated in one go.

I thought that was really the point of a custom / vanity nameserver when used with an AnyCast type setup.

Thoughts?

 

Yes I realise that every domain that uses my server needs a DNS update of course - at least initially to e.g. to CloudFlare.

Whilst your point is correct, I was not thinking to change the vanity nameserver - but the IP address of the host server might change.... therefore, if I want to move Datacentres / host providers, or change server from serverA to serverB - it would simply be a matter of updating the IP address of where my vanity nameserver points to - rather than having to mass update all client domain DNS (since they would still use my vanity nameservers.

The genesis of my thinking is due to a recent DNS failure (2 in one month) at current host which resulted in some hours downtime. I was wondering how best to handle a host DNS outage (they use AnyCast which is fantastic --- when it works )

I have sent you a conversation request with some further thoughts...

Thank you for all your thoughts and knowledge thus far! I appreciate your time :-0

 

Yes, it looks like to use a vanity nameserver in CF it requires the business plan.

So I guess the only answer is to import each client domain into CF separately!

Then point each domain to my vps.

Going to be a long week!

 

Actually - I've just discovered something very interesting..... this post is as much for my record - as for your interest!

I set up a test server with primary name mydomain123.com on 123.456.789 server IP, and set ns1.mydomain123.com and ns2.mydomain123.com nameservers

Then I set up CF for the primary server domain: mydomain123.com

In domain registrar for mydomain123.com I pointed to the dns nameservers that CF gave me. I also added my child nameservers: ns1.mydomain123.com > 123.456.789 and ns2.mydomain123.com > 123.456.999

Then in CF I paused everything to just use their DNS - checked the DNS / A records etc all pointing to server.

Tested mydomain123.com and it resolved fine - part 1 complete!!

Here's the magic:

Then in CF I added a NS record in the DNS setting page for the primary server domain and got this result;

NS | mydomain123.com | managed by ns1.mydomain123.com
NS | mydomain123.com | managed by ns2.mydomain123.com


Then I went to a completely different domain myxyz.com - in another registrar and pointed its nameservers to ns1.mydomain123.com (also set up an account for myxyz.com on my server)

guess what! It worked...

myxyz.com adopted the nameservers from my CF primary domain!

I have yet to test all functions... but an intodns report looks totally fine - all records appear to be correct

So now, if I have got this right - I can simply point any client domains using the same as above and once they propagate to my server domain child nameservers - I'm all set.

Can you see any flaw in this method - other than of course the initial delay in getting the client domain to point to my child nameservers?

 

whatsmydns shows the client domain as using my primary domain child nameservers (which are at the registrar and also added to CF)

So is the client domain simply bypassing CF ? Presumably this is not an issue so long as the nameserver on the server does not change - and so long as I don't want any other features from CF for the client domain.

When I tried this - the client domain that's pointing to the master domain's child nameservers - resolved in under 1 minute - so I'm not entirely sure how that can be a negative. It must still be utilising CF's DNS fast propagation.

Anyway, for now it looks like I have an initial solution to enable me to move server IPs without having to update dozens of client domains. I can then slowly migrate each domain to CF as time permits.

If you can think of any downsides - please let me know!

 

Yes I got that - not really any benefit to the client domain.... will retest this through tomorrow !

Cheers