The IPS functionality
This is one of the well-sought features, and IPS are used in conjunction with a feature called virtual patching, which is quite interesting.
Let's assume that there is a vulnerability present in a public web server that is still not patched. In a generic approach, an attacker can easily fire an exploit and send the payload to the server. However, as a part of virtual patching, the IPS will block the exploit even though the vulnerability is present on the server.
This is especially useful in many cases, where upgrading software might not be possible due to business reasons.
A real-world example
We had an important database server running on MySQL. After a few months, a high-risk vulnerability was discovered on the MySQL version that we were running and as a part of the compliance program, we had to mitigate the risk, which is mostly done through the monthly patching activity via Spacewalk.
However, it was a very important database server, and any case of stopping the MySQL...