We use Ixia BreakingPoint as a security tester oriented to test other network security solutions. Validation is needed in case of major changes in your network security infrastructure. It might be a change in your HW, major change in architecture or if you just want to be sure, that new feature will not have an effect on the performance of your security solution. We use it for IDS, anti-malware, anti-DDoS, anti-ransomware, etc.
You can use it also for testing the impact of an attack on your valid application traffic and infrastructure. Ixia BreakingPoint provides us with advanced network security features.