How to Setup DNS For SharePoint Site

Follow the steps below if you need to know how to set up DNS for a SharePoint site.

1. Go to Central Administration
2. Go to Operations tab. Under Global Configuration section, select Alternate access mappings
3. On Alternate Access Mappings page, click on Edit Public URLs
4. Select Alternate Access Mapping Collection, i.e. your  newly created website
5. Under Intranet type in the internal web address that you would like for your site
6. Under Internet type in the external (public) web address that you would like for your site
7. Click “OK” when finish”
8. Remote desktop to the MOSS server farm where your SharePoint site was deployed
9. Go to IIS Manager
10. Expand the Web Sites folder, right click on your website
11. On the Web Site tab, click on the Advanced button. Click “Add” button
12. On the Add/Edit Web Site Identification screen modify to suit your site according to the following:
IP address: (All Unassigned)
TCP port: 80 (has to be 80)
Host Header value: (This is the external/public address of your website that was entered in step 6)

13. Click OK to save all changes
14. On the Web Site tab, click on the Advanced button. Click Add.
15. On the Add/Edit Web Site Identification screen modify to suit your site according to the following:
IP address: (All Unassigned)
TCP port: 80 (has to be 80)
Host Header value: (This is the internal address of your intranet website that was entered in step 5)

16. Click OK to save all changes. (OK for couple of screens so that you are looking at main IIS Web Sites folder)

Testing that the DNS works

1. On your local machine, open Windows Explorer
2. Go to C:\WINDOWS\system32\drivers\etc folder and open up the hosts file.
3. Add the IP address entry corresponding to your website i.e.         xxx.xxx.xxx.xxx      <extranet/intranet URL>
4. Save the file
5. Open IE browser and type in the extranet/intranet URL to check that you can access the site.  If you can view the site, then you have setup DNS.

Reference:

http://sharepointdotnetwiki.iblogger.org/2009/12/dns-setup-in-sharepoint/