The real life case to illustrate the importance follows. The consequence of deleting such an object is that in places where it is used the system will automatically replace it with the object “Any”, which in most of the cases not what the admin wants.

This warning message has a button named “Where used?”, which if pressed, will show all the places this object is part of. My recommendation when getting such warning is NOT to delete the object, but to check all the Rules where it is being used, remove it with due diligence from them and only then to delete it. Not everyone unfortunately reads and follows them. Checkpoint allows admins to delete the object being used in Security Rules while warning about the consequences. It happens especially with sysadmins coming from the Windows world where warnings are frequently ignored and you just click through them. In my experience this one can be most dangerous (read below). Deletion of an object which is being used (cannot happen in R80 by design). The list relates to the firewall versions R55-R77.30 with the added remediation means of R80, thanks to Tomer Sole's remarks on CheckMates CheckPoint Community forum as I myself haven’t gathered enough experience with this version yet.

Here is my ‘top’ list of the frequent errors which beginners (and not so much) do. Different versions, different topologies and technologies brought different issues with it, but what remains constant is the mistakes people do. In 10 years of my daily work with Checkpoint firewalls I have been to many troubleshooting sessions.