File drbd.firewalld.xml of Package yast2-drbd

<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>SUSE YaST DRBD</short>
  <description>This allows you to open various ports related to SUSE YaST DRBD. Port 7788 and higher is recommend.</description>
  <port protocol="tcp" port="7788"/>
</service>