Enable TLS Protocol Logging in IIS

applicationHost.config

 <!--
 Source:
 https://blogs.microsoft.com/microsoftsecure/2017/09/07/new-iis-functionality-to-help-identify-weak-tls-usage/
 -->
 
 <site name="Default Web Site" id="1" serverAutoStart="true">
   <application path="/">
     <virtualDirectory path="/" physicalPath="C:\inetpub\wwwroot" />
   </application>
   <bindings>
     <binding protocol="https" bindingInformation="*:443:" />
   </bindings>
   <logFile>
     <customFields>
       <clear />
       <add logFieldName="crypt-protocol" sourceName="CRYPT_PROTOCOL" sourceType="ServerVariable" />
       <add logFieldName="crypt-cipher" sourceName="CRYPT_CIPHER_ALG_ID" sourceType="ServerVariable" />
       <add logFieldName="crypt-hash" sourceName="CRYPT_HASH_ALG_ID" sourceType="ServerVariable" />
       <add logFieldName="crypt-keyexchange" sourceName="CRYPT_KEYEXCHANGE_ALG_ID" sourceType="ServerVariable" />
     </customFields>
   </logFile>
 </site>