Hi Anubhav,
There is no "name" or DNS. If you want to keep your firewall rules up to date, I would recommend to keep checking the following page and updating your firewalls:
Azure IP Ranges and Service Tags – Public Cloud
https://www.microsoft.com/en-us/download/details.aspx?id=56519
If this is helpful please accept as answer or upvote.
Best regards,
Dillon Silzer | Cloudaen.com | Cloudaen Computing Solutions