Which three are required by URL Analysis?

To use URL Analysis, you will need to have a Tier-1 gateway and a Layer 7 DNS firewall rule on the NSX Edge cluster. Additionally, you will need to configure an OFW rule allowing traffic OUT to the Internet. Lastly, a medium-sized edge node (or higher), or a physical form factor edge is also required as the URL Analysis service will run on the edge node. For more information, please see this VMware Documentation article[1], which explains how to configure URL Analysis on NSX.

[1] https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.1/nsxt_31_url_analysis/GUID-46BC65F3-7A45-4A9F-B444-E4A1A7E0AC4A.html