multi server dns - chain or any to any?

[stars]

We are using multi server dns as described http://help.directadmin.com/item.php?id=97

Currently we define on each box connections to every other box - so list of external servers is getting longer and longer and harder to maintain.

Couldnt we just define a on each box connection to another box?

Does multi server support 2way data exchange? Does it exchange only local zones or does it also forwards zones imported prom another box?

 

[SeLLeRoNe]

Usually NS are 2 or 3 (suggested 3 geographical), not more, isn't that needed, so, maybe i would suggest you just 2 basic VPS with DirectSlave (that you can find here on the forum) and set just 2 server in the multi-server option that are the VPS with DS installed, so, every server will point just to those 2 (or even 3 if you want to) and tha list should not be that long anymore

I dont see really any reason to have more than 3 NS.

Or, if you dont wanna take 2/3 VPS just for this, define 2 (or 3) of your DirectAdmin Server to be the main NS and point all the other DA Servers just to those.

Regards

 

[zEitEr]

Couldnt we just define a on each box connection to another box?

Each server participating in a multiserver scheme should have a full list of other servers.

Does multi server support 2way data exchange? Does it exchange only local zones or does it also forwards zones imported prom another box?

No, it does not share anything further when importing from another server.
So it does not work this way: S1 -> S2 -> S3.
It works only this way: S2 <- S1 -> S3
In both examples changes were initiated on S1.

 

[stars]

Thanks for clearing this out!

 

[stars]

Thanks for clearing this out

No, it does not share anything further when importing from another server.

I think You meant exporting. Every local change in DNS is exported to listed multiservers.

 

[zEitEr]

I think You meant exporting. Every local change in DNS is exported to listed multiservers.

No, I was saying about importing (accepting, receiving).

Yes, every local change in DNS is exported to listed multiservers.
And multiservers when receiving ( = importing) data do not send it to other servers. It's done I guess to avoid loops.

 

[stars]

Well my current setup was any to any so every production box (as well as my 2 dns boxes) had set of local and all copy of all other records. I thought it was necessary for checking whether domain already exists on any other of my boxes before adding it.

If I setup

BOX_1 -> DNS_BOX <- BOX_2

I will end up with DNS_BOX with full data and BOX_1 or BOX_2 with only local data.

So I should setup

BOX_1 -> DNS_BOX <- BOX_2
DNS_BOX -> BOX_1
DNS_BOX -> BOX_2

Am I correct?

 

[SeLLeRoNe]

You're correct, but.. actually i'd never used multi-server setup to check if i already have a domain on server, i dont see any reason for that... a new domain registration already control if domain is already registered, and i suppose that you should know what domains you have and/or your customers does

Regards

 

[zEitEr]

So if you have 2 webservers (BOX_1, BOX_2) and 2 DNS servers (DNS_BOX_1, DNS_BOX_2), then the every single server should have 3 other server listed on multiserver page:

BOX_1:
1. BOX_2
2. DNS_BOX_1
3. DNS_BOX_2

BOX_2:
1. BOX_1
2. DNS_BOX_1
3. DNS_BOX_2

DNS_BOX_1:
1. BOX_1
2. BOX_2
3. DNS_BOX_2

DNS_BOX_2:
1. BOX_1
2. BOX_2
3. DNS_BOX_1


So wherever you change DNS records it would spread to the other 3 servers, and keep all the 4 servers with synced and actual data.

 

[stars]

actually i'd never used multi-server setup to check if i already have a domain on server, i dont see any reason for that...

There cannot be 2 zones for same domain on 2 different boxes, esprecially if boxes exchange DNS data. This would end up in overwriting older data with newly created. It matters also if You add subdomain as domain (domain on one box, and different subdomians of that domain on other boxes). Or if You move domains between boxes. Domain Check and User Check on multiserver setup is essential for us as we don't want any duplicated usernames or domains on any our BOX. We manage all our clustered DA servers from our own external tool/panel.

 

[stars]

So wherever you change DNS records it would spread to the other 3 servers, and keep all the 4 servers with synced and actual data.

This was my point for asking question in the first place. You suggested any to any. It is quite simple for setup as above. But when there are 20+ boxes its very hard to manage - you have to add new server to every old server, and add all old servers in new server.

 

[zEitEr]

There cannot be 2 zones for same domain on 2 different boxes, esprecially if boxes exchange DNS data.

Directadmin Multiserver function has a function to control existence of a domain on a remote server, in other words it won't let anybody to create a domain if it exists on a remote server. Of course you should tick a checkbox to enable this feature on Multiserver page.

are 20+ boxes its very hard to manage

Write a proxy server then which would use API and transfer zones to your 20+ servers.

So you add only 1 DNS_PROXY to all of your 20+ DA_BOXES and your custom DNS_PROXY makes its job and transfer zones between DA boxes using Directadmin API. Of course DNS_PROXY should have a list of all your servers.

Or use rsync to sync named.conf with zones between the servers.

 

[zEitEr]

By the way using DA Multiserver function to sync 20+ DA boxes will slow down creating/changing domains, so I'd rather not use it.