Setting Up DNS for 3 Subdomains in OSX Capitan

I don't think you need a new computer/DNS server. I think you need to become more knowledgeable with respect to DNS and DNS server configuration. So I think you will be better served by finding a forum dealing with DNS issues. This community is for discussing El Capitan issues.

>System Preferences...>Network

click on your network connection

click on the DNS tab

add the internal DNS Servers to your list first

end the list with the google DNS server unless you have an internal DNS that handles outside requests along with your internalized sites.

anything past that consult with your netadmin on site or wherever he/she might be.

Your IP ranges 10.0.1/2/3.X are subnets, not subdomains

Also, you should post in the OS X Server group

In the DNS server settings, you need to set the desired IP address to the hostname of the service running. (Website, FTP, VPN, etc.)

Follow the Krypted guide to get started

http://krypted.com/tag/dns/

Lastly, do you really need three subnets?

How big is your organization?

I don't believe at all that BobTheFisherman is being offensive when he says "I don't think you need a new computer/DNS server. I think you need to become more knowledgeable with respect to DNS and DNS server configuration.". I would have to agree with him.

For example what you describe are not three sub-domains they are three separate domains. Three sub-domains would look like sub1.company.com, sub2.company.com and sub3.company.com where each sub1, sub2, sub3 is a sub-domain of company.com furthermore the other issues of 10.0.1.x, 10.0.2.x and 10.0.3.x being able to communicate and ping each other is not really a DNS issue but is more a routing/firewall issue.

I will say that Apple's DNS server can handle multiple domains, even sub-domains and do this for multiple different network ranges as long as your router and firewalls allow all the networks to talk to each other. You need a router to 'route' between the different network number ranges i.e. 10.0.1.x and 10.0.2.x.

Apple's Server software is not suited to be the router although in theory it might be able to do it, more often these days this would be done by a high-end network switch.

For your information Apple's DNS server software is BIND also known as named

I would add to others comments to suggest you use Apple's Knowledge Base (link below) to search for DNS configurations and solutions....

Apple - Support - Search

Yes this single Apple DNS server can act as DNS server for multiple subnets. All you need to do is make sure all the devices know to use it as their DNS server which as stated by chattphotos is done in System Preferences -> Networking on a Mac, although it will be easier overall to use your DHCP server to tell all your DHCP clients Mac, PC or other, what the address of the DNS server is.

Note: The one thing Apple's DNS server is totally unsuited for is dynamic DNS. This is used in particular by Microsoft's Active Directory system. So if you are using Active Directory you would be best using Microsoft's DNS server and DHCP server.

Yes Bonjour uses mDNS aka. multicast DNS. Yes it normally only works on a single subnet.

There is a system called Wide Area Bonjour which in theory can be used across subnets, in particular the AirPort Extreme used to support this - I don't know if the latest model still does. There is also a class of products called Bonjour Gateways which are designed for enterprise i.e. 'large' networks and designed both to help reduce the potentially large amount of Bonjour traffic caused by lots of Macs, iOS devices, printers, etc. all using Bonjour and also as a way of passing Bonjour between subnets.

See http://www.aerohive.com/solutions/technology/bonjour-gateway.html

and https://meraki.cisco.com/technologies/bonjour-gateway