Solved

Maintaining internal and external DNS

Posted on 2012-12-28
7
416 Views
Last Modified: 2013-01-08
Feels weird to be on this side of the question.  

I have users who need to connect to a vendor via both External and internal IP addresses.  Let me explain.

Lets say that your client is microsoft (not really).  I need to have the user resolve an ip address for web1.microsoft.com but this address is a private address (not in Microsoft's external DNS) that needs to go through a specific VPN connection.  The user ALSO needs to connect to www.microsoft.com via the internet.  

I have the routing correct.  The way we have been doing this in the past is to user local "host" files.  We are getting too big to manage these files.  I need to get them on DNS and manage them from there.

I tried added a microsoft.com primary zone with a forwarder to 8.8.8.8 (google external DNS).  The web1.microsoft.com address works but I then can not resolve www.microsoft.com.

I am running DNS on Windows 2008 R2 domain controllers.

Thanks for the help.

Mav
0
Comment
Question by:mav7469
7 Comments
 
LVL 28

Accepted Solution

by:
becraig earned 500 total points
Comment Utility
Though I don't like the approach you are taking and would prefer to stay with host files to avoid issues with name resolution down the road, here is an idea.

Don't create a Microsoft.com zone, rather create a ww1.Microsoft.com zone then create an empty A record to point to the address you need.

All other requests will be resolved by public dns.
0
 
LVL 3

Author Comment

by:mav7469
Comment Utility
The only issue I can see with this idea is that we are talking about dozens of clients with dozens of addresses each.  Will that overload the DNS server?  Is there a limit as too the number of zones?

Thanks
0
 
LVL 39

Expert Comment

by:footech
Comment Utility
I'm having trouble picturing your situation.  In your original question you mention one site that needs to resolve to an internal IP and one that needs to resolve to an external IP.  Then in your last post you mention dozens of clients with dozens of addresses.  Can you describe that better?  What is the number of addresses that need to resolve to an internal IP vs. the number that should be resolved by public records?  And are these all for the same domain or for different ones.

The solution that becraig proposed is the route to take if you have one site that needs to resolve to a different IP than what is present in public DNS records.

A flip of that, if you have just one site/host that needs to be resolved by public records, while the rest are resolved by internal records, is also possible.  To do this, you would have a zone for "example.com", with all the internal A records, then for a record you want to resolve by external records create a delegation that points at the SOA for the domain in public DNS.  Let me know if you need more detail or you can find instructions here:
http://blogs.dirteam.com/blogs/acefekay/archive/2009/08/08/split-zone-or-no-split-zone-can-t-access-internal-website-with-external-name.aspx
0
How to improve team productivity

Quip adds documents, spreadsheets, and tasklists to your Slack experience
- Elevate ideas to Quip docs
- Share Quip docs in Slack
- Get notified of changes to your docs
- Available on iOS/Android/Desktop/Web
- Online/Offline

 
LVL 28

Expert Comment

by:becraig
Comment Utility
I don't follow

The only issue I can see with this idea is that we are talking about dozens of clients with dozens of addresses each.  Will that overload the DNS server?  Is there a limit as too the number of zones?


Are you saying you expect to have personalized host records for multiple public dns sites ?

If you don't mind me asking what is the aim here ?
If this is for traffic management you may want to look into a traffic management solution or an ISA/TMG server.

I cannot see a scenario where you would need to have a host record on your dns server for a hundred or more public zones (namespaces you do not own)
0
 
LVL 3

Author Comment

by:mav7469
Comment Utility
The only issue I can see with this idea is that we are talking about dozens of clients with dozens of addresses each.  Will that overload the DNS server?  Is there a limit as too the number of zones?

I was speaking to the answer given to create a zone for each host file entry.

Right now, we have 105 different entries in our host files that we have to manage on over 400 computers.  These host files can change at the whim of our client (they change a process to a different server for example).  Becasue we can not manage the host files via script, I want to move them to DNS so I only have to touch one place to make changes instead of 400 different computers.
0
 
LVL 28

Expert Comment

by:becraig
Comment Utility
Both scenarios are viable and if your dns server is only available on your intranet (via vpn or direct access)  You can also script one host file and propagate to all the clients every time a change is made (Since you would have to be notified in the case of DNS as well).

The choice is your but the solutions offered above would work, a little more visibility into:
Approximately how many public domains are you spoofing ?
Are the clients only using your dns servers for name resolution ?
Is your dns server available to your clients on the internet or only on the intranet ?
would help to create a better view of what is required.
0
 
LVL 25

Expert Comment

by:DrDave242
Comment Utility
It sounds like your client has identical public and private DNS domain names.  That's never a good idea, although I think this is the first time I've considered the administrative nightmare that it can cause for a partner in an extranet scenario.  105 entries in your hosts files?  That's insane.

It seems likely that most of the addresses you'll need to resolve are private addresses.  If that's the case, you can use either conditional forwarders or a stub zone to send those queries to your partner's DNS servers.  Then you don't have to update anything when they make changes internally, and you can create forward lookup zones on your DNS servers (as has already been mentioned) for the public addresses, which aren't likely to change much.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

BIND is the most widely used Name Server. A Name Server is the one that translates a site name to it's IP address. There is a new bug in BIND (https://kb.isc.org/article/AA-01272), affecting all versions of BIND 9 from BIND 9.1.0 (inclusive) thro…
Security is one of the biggest concerns when moving and migrating your data from your on-premise location to the Public Cloud.  Where is your data? Who can access it? Will it be safe from accidental deletion?  All of these questions and more are imp…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

772 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

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now