Fixing conflict between internal and external domain with same name via internal DNS entries

Posted on 2014-10-13
Last Modified: 2014-10-13
On newly deployed Windows Server 2012 R2, followed the advice given on another question on naming the internal domain the same as the external domain for the sake of username consistency for using with Office365.

I wondered at how this would affect DNS, but when you are revamping your deployment plan in mid-deployment...

So of course this has led to the external website not resolving properly internally as well as issues with any of the external domains DNS records being recognized internally.

I beleive that this can be fixed by the appropriate entries in the DC's DNS table, however, that is beyond my (admittedly basic) DNS knowledge.

I believe that I probably need to recreate all external DNS entriesas static entries only.

I am unsure of many things though:

#1. Should I be adding these entries to the existing internal domain lookup zone or creating a new zone?

#2. If a new zone, what kind of new zone should it be? (Primary, Secondary, Sub)

#3. If a new zone, do I need to change any of its default properties?
Question by:MJCS
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 2
LVL 16

Accepted Solution

Joshua Grantom earned 500 total points
ID: 40377900
It will be in the existing zone if your internal domain is the exact same name as your external.

Once you create the a, cname, and mx records to mirror external dns, everything should be accessible after that.
LVL 16

Expert Comment

by:Joshua Grantom
ID: 40377925
do you have any external sub-domains?

Author Comment

ID: 40377926
Should propagation be immediate?
Forrester Webinar: xMatters Delivers 261% ROI

Guest speaker Dean Davison, Forrester Principal Consultant, explains how a Fortune 500 communication company using xMatters found these results: Achieved a 261% ROI, Experienced $753,280 in net present value benefits over 3 years and Reduced MTTR by 91% for tier 1 incidents.

LVL 16

Assisted Solution

by:Joshua Grantom
Joshua Grantom earned 500 total points
ID: 40377938
clients may need to flush dns cache

Run this from a command line.
ipconfig /flushdns

Author Comment

ID: 40377987
Do I need to worry about spf/txt records?
LVL 16

Assisted Solution

by:Joshua Grantom
Joshua Grantom earned 500 total points
ID: 40377999
I wouldn't worry about spf records because you are using Office 365. Only the external spf will be read by other mail servers.

Featured Post

MIM Survival Guide for Service Desk Managers

Major incidents can send mastered service desk processes into disorder. Systems and tools produce the data needed to resolve these incidents, but your challenge is getting that information to the right people fast. Check out the Survival Guide and begin bringing order to chaos.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

I've written instructions for one router type, but this principle may be useful for others of the same brand and even other brands of router. Problem: I had an issue especially with mobile devices that refused to use DNS information supplied via…
Issue: One Windows 2008 R2 64bit server on the network unable to connect to a buffalo Device (Linkstation) with firmware version 1.56. There are a total of four servers on the network this being one of them. Troubleshooting Steps: Connect via h…
In this Micro Tutorial viewers will learn how to use Boot Corrector from Paragon Rescue Kit Free to identify and fix the boot problems of Windows 7/8/2012R2 etc. As an example is used Windows 2012R2 which lost its active partition flag (often happen…
This tutorial will walk an individual through the steps necessary to join and promote the first Windows Server 2012 domain controller into an Active Directory environment running on Windows Server 2008. Determine the location of the FSMO roles by lo…

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question