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DNS problem- company LAN and external website share domain name-web host has multiple websites on same IP address...

FIFBA
FIFBA asked
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Last Modified: 2008-03-06
I have a client whose LAN, domain.com, has the same domain name as their external website, domain.com.  Usually in this situation, you just need to add an A record for www and point it to the IP address of the external website. We did this, and ran into the following problem:

It turns out that the web host is using the same IP address for multiple sites.  When a user inside the domain.com LAN goes to www.domain.com they are directed to the proper IP address...but they get the hosting company's default web page, not domain.com's web page.  Is there a problem with the host headers?  Has anyone seen this problem before?  The customer formerly hosted the website internally via IIS.  Does this have something to do with the problem?

Windows 2000 Server, XP clients

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Erik BjersPrincipal Systems Administrator

Commented:
You need to contact the company who domain.com was registered to and have them add an A record for your web server that points to your public address.

Author

Commented:
There is already an A record in place that points to the public address.  The public is able to access the website just fine...it's the users inside the domain.com LAN that are unable to access it.  DNS is resolving correctly from within the LAN (it goes to the public IP address specified in the 'www' record we created on the internal DNS). Problem is that the public IP is actually shared by multiple websites.  When a LAN user types www.domain.com, the local DNS is able to point the browser to the correct IP address; however, the host header must be missing since the Apache server hosting the external website is not able to tell which website the user was requesting and sends the user to the web hosts default page. The LAN user's request is resolved to an IP address but something is missing. The web host has several companies with a similar setup (i.e. sharing same internal/external namespace) and has not come across this problem before. The problem is likely within our LAN.
Erik BjersPrincipal Systems Administrator

Commented:
try pointing your internal clients to the privat IP
FIFBA,
Sounds like your A record doesn't match exactly what their A record is.  Could be case sensetive.
If you don't mind, from outside your lan, go to your company website and paste the exact URL here.
Then from inside your lan, do the same thing and paste it here.

I used to be the webmaster for numerous sites set up this way on a microsoft server.  All websites had the IP address that were the same but they were controlled by the host header.  I think that you are correct that the issue lies with your internal DNS record for the website.
It's always a bummer to hear that an internal site's dns was set up with the exact domain name as the public one.
My rule is to always go with something like domain.local instead of .com but too late for that.  I have two sites that I support that were set up with their .com.

Mike

Author

Commented:
I have checked the IP address with the web host 3 times and ran an nslookup on the domain.  The numbers match. If you ping domain.com from outside the LAN, it is hitting the same IP address provided by the web host.  If you type this IP address in an Internet Explorer window, however, you do not get the domain.com website- you get the hosting company's default web page.  So obviously we can't access the web page by IP alone and the usual remedy for this situation (create a www record pointing to site) is only redirecting the user to an IP address.  Internal DNS is resolving correctly, just must not be sending host header info since it doesn't get directed to the proper web page after reaching the IP address.  I have several clients who have been set up with the same interal/external domain name but have never run into this problem.  Usually you just create a www record and you're done. Any more ideas?
Erik BjersPrincipal Systems Administrator

Commented:
Sorry I'm out

You may want to post a pointer to this question to get new blood in on it.
The only suggestion that I may have remains that your A record may be case sensetive.  

Author

Commented:
The A record is pointing to a number...Not sure what you mean by an A record being case sensitive.  Are you referring to the WWW being case sensitive?  
yes

Author

Commented:
Do you think this is a real possibility?  Would changing the www to WWW affect the host header portion of the packet?  DNS is resolving properly to the proper address...
Erik BjersPrincipal Systems Administrator

Commented:
Yes it can affect it.

Author

Commented:
Would this have something to do with the website being hosted on an Apache server?  I will try the solution but would be surprised if it works as the host has never run into this problem and has numerous clients where the internal/external websites are the same. Also, it seems that if this were the case that a user would be required to type http://WWW.domain.com  (WWW in caps).  I'm thinking that it is significant that the website was formerly hosted on the LAN...Could there be something remaining in IIS ( on the LAN domain controller) that drops the host header since it thinks the address is internal?  I appreciate everyone's help.  Does anyone have any other ideas before I go onsite?
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Commented:
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