dns config check

[jjohnsoncantell]

Greetings,

 

I have two dns servers (dc1 & dc2 for example sake) running onsite and want to be sure that my dns config isnt causing slow resolution for accessing sites or problems during startup resulting in 5719 & 1055 errors. My setup is as follows

 

dc1:

Preferred dns: dc1

Alternate dns: dc2

 

dc2:

Preferred dns: dc1

Alternate dns: loopback address

 

Both servers have our dns forwarders added. I have read on some sites that loopback addresses shouldn't be used, some say it should. Some sites say the servers should look to eachother for preferred, some say they should look to themselves. What are your best practices for multiple dns setup?

 

Thank you.

[Blue_Cookeh]

dc1:

Preferred dns: dc1

Alternate dns: dc2

 

dc2:

Preferred dns: dc2

Alternate dns: dc1

 

This is how it should look. The DNS servers on each DC should have an upstream resolver to Google/your ISP/whatever to avoid long queries to the DNS root servers.

 

EDIT: Sorry, should be using the IP addres, NOT loopback. It's commonly debated, but just don't use loopback in the primary field.

Edited December 14, 2016 by Blue_Cookeh

[brougham]

Up until the last three months I did it the same way as you but after reading Active Directory Insights (Part 1): Configuring DNS on domain controllers :: Windows Server 2012 :: Articles & Tutorials :: WindowsNetworking.com and Best Practices for DNS Configuration in an Active Directory Domain | Dell Ireland

 

They now suggest-

DC1:

Pref : DC2

Alt : DC1

 

DC2:

Pref : DC1

Alt : DC2

 

If you have multiple sites (DC1 and DC2 together and DC3 remote) then they say-

DC1: pref- DC2, alt1- DC3, alt2- DC1

DC2: pref- DC1, alt1- DC3, alt2- DC2

DC3: pref- DC1, alt1- DC2, alt2- DC3

[jjohnsoncantell]

Therein lies my problem, it seems to be a whatever works kind of thing. Surely there is only one correct way to configure it. Personally it makes sense to me to have each dns server to look at itself first then the other but I suppose if they both have forwarders then it doesnt matter if its the other way around. The only time I can think it would be an issue is if a dns server is set to look to itself first then it could cause a delay in starting the network on a reboot.

[mikkydoos]

Up until the last three months I did it the same way as you but after reading Active Directory Insights (Part 1): Configuring DNS on domain controllers :: Windows Server 2012 :: Articles & Tutorials :: WindowsNetworking.com and Best Practices for DNS Configuration in an Active Directory Domain | Dell Ireland

 

They now suggest-

DC1:

Pref : DC2

Alt : DC1

 

DC2:

Pref : DC1

Alt : DC2

 

If you have multiple sites (DC1 and DC2 together and DC3 remote) then they say-

DC1: pref- DC2, alt1- DC3, alt2- DC1

DC2: pref- DC1, alt1- DC3, alt2- DC2

DC3: pref- DC1, alt1- DC2, alt2- DC3

 

 

 

This is now it should be according to MS.