EDR: App Control Integration Fails with "The server is not accessible"

Products

• Carbon Black EDR (formerly Cb Response)

Issue/Introduction

When saving the settings for Application Control integation, a message appears "The server is not accessible" 

Environment

• EDR: All Versions
• AppC: All Versions

Cause

Traffic to 443 is being blocked for the EDR server IP or address is incorrectly entered

Resolution

1. Make sure the Address does not contain https://, it should only be the FQDN address. Example: myserver.mydomain.com. If the error continues, proceed to step 2
2. Run the following command to verify the server can properly resolve the FQDN

   nslookup myserver.mydomain.com

3. Run this command to confirm the port is not being filtered by a firewall on the AppC server side or in-between. If it comes back as "filtered" the port is being blocked for the EDR server IP.

   nmap -Pn -p 443 myserver.mydomain.com

   Filtered by Firewall:
   
       PORT STATE SERVICE
       443/tcp filtered https
   
   Not filtered:
   
       PORT STATE SERVICE
       443/tcp open https