Exam PCNSE topic 1 question 383 discussion

A firewall administrator is investigating high packet buffer utilization in the company firewall. After looking at the threat logs and seeing many flood attacks coming from a single source that are dropped by the firewall, the administrator decides to enable packet buffer protection to protect against similar attacks.
The administrator enables packet buffer protection globally in the firewall but still sees a high packet buffer utilization rate.
What else should the administrator do to stop packet buffers from being overflowed?