Internal Clients not resolving to internal Ip

Hi Team,
We have a standard domain network running server 2012.

now the problem is as follows
Any internal client when they ping is supposed to
mail.abc.com.au resolves to 192.168.4.2

Now what happens sometimes is that every morning when someone turns their PC on they might get an issue where out of blue the DNS starts to resolve to the WAN IP of our network

If i flush the DNS the issue is resolved

Has any one faced a similar issue.

And the strange part of that it happens even to the machines that were left in the office overnight s well and not only to the ones that were out of the office.

All clients get IP from DHCP server 192.168.4.3
and gives out DNS' as 192.168.4.3 and 192.168.4.4

Any ideas?
LVL 4
Costas GeorgiouNetwork AdministratorAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

TropicalBoundCommented:
Do the PC's ave wireless NICs that are connecting to an external network?

Have you checked your internal DNS to see if there are multiple entries for mail.abc.com.au?
0
stu29Commented:
A lot of times this will happen when your DNS server does not respond in a normal amount of time to a request.  The client can not resolve the internal IP and so looks to the root hints and gains the External IP.  By the time you get to the computer in question .... DNS works again on your server.. but the local cache already has the external IP. So when you clear the cache, all is well.

Also .. this can happen if there is an external IP address added to the IP configuration for DNS servers as a backup.

Also .. if you have split routes to the destination, and one goes down .. then you do not see the route to the internal IP address and are sent to the external.

I would start with DNS performace and work out from there to narrow it down.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Faruk Onder YerliOwnerCommented:
Could you please check DNS viruses in your computer.?

one of them you can check as below.

http://www.dcwg.org/fix/
0
Simplify Active Directory Administration

Administration of Active Directory does not have to be hard.  Too often what should be a simple task is made more difficult than it needs to be.The solution?  Hyena from SystemTools Software.  With ease-of-use as well as powerful importing and bulk updating capabilities.

Costas GeorgiouNetwork AdministratorAuthor Commented:
@stu29

Thanks for your response guys

I also started from the DNS forwarders and then yesterday i already removed all the DNS forwarders from the server.
But this morning got the same issue

I think its the way the DNS is working right now.
There are some machines that even after flush DNS still resolve to teh WAN IP
0
Costas GeorgiouNetwork AdministratorAuthor Commented:
I have two DNS servers and i have made some change to the primary and secondary zones and shall get back to you with an update.
Thanks
0
stu29Commented:
When you are having the issue ... pull up a command prompt on the client and type nslookup ... does it list your internal DNS server?

Is your internal namespace abc.co.au or abc.local (or something else)?
0
Costas GeorgiouNetwork AdministratorAuthor Commented:
I have two DNS servers and i have made some change to the primary and secondary zones and shall get back to you with an update.
@ stu29
Nslookup shows the right server and have added a PR records for the DNS server as well which was missing

Thanks
0
Costas GeorgiouNetwork AdministratorAuthor Commented:
Thanks for the response guys

The issue has been resolved

@ stu29 : thanks for the hints they were in the right direction

And also thanks to others participating

Solution: The issue was with DNS zone and name servers for the secondary zone.
0
stu29Commented:
ConnectCG .. glad you working it out!
0
Costas GeorgiouNetwork AdministratorAuthor Commented:
We were able to resolve the issue , however the team did provide information relevant to the issue and in the right direction.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Windows Server 2012

From novice to tech pro — start learning today.