Having a source and destination SharePoint site with the same URL is possible, making it difficult for your connections in ShareGate Migrate.
You can circumvent this problem with the information in this article.
How-to
Add alternate access mappings
Go to the central administration on your source SharePoint. Look for the option Configure alternate access mappings. Make sure to choose the proper Alternate Access Mapping Collection. Click Edit Public URLs and write something like http://migrationSource in the Custom field. This will let you use http://migrationSource as the hostname, making it possible to access a site on your source like this, for example, http://migrationSource/sites/Sharegate.
Modify the hosts file
You will need to use Notepad as an administrator to modify this file. You will need to add the IP address of your source SharePoint server followed by the hostname from the alternate access mappings, in this case: migrationSource. Add a line for the destination as well with the original URL. It should look like this :
This will allow you to use the URL you created in the Alternate Access Mapping to access your source SharePoint server. Adding the original URL with the destination Sharepoint server's IP address will make all calls to that URL go to the destination server.
Here is the location of the hosts' file for multiple versions of Windows :
For Windows 8
- Press the Windows key.
- Type Notepad in the search field.
- In the search, right-click Notepad and select Run as administrator.
- In Notepad, open the following file:
c:\Windows\System32\Drivers\etc\hosts - Make the necessary changes to the hosts file.
- Click file -> Save to save your changes.
For Windows 7 and Windows Vista
- For Click Start -> All Programs -> Accessories.
- Right-click Notepad and select Run as administrator.
- Click Continue on the "Windows needs your permission" UAC window.
- When Notepad opens, click file -> Open.
- In the filename field type:
C:\Windows\System32\Drivers\etc\hosts - Click Open.
- Make the necessary changes to the hosts file.
- Click file -> Save to save your changes.
With those modifications, you should be able to connect to your source and destination servers through ShareGate Migrate and complete your migration.