topic Has anyone been able to correlate performance issues due to the number of security rules present? in General Topics

Has anyone been able to correlate performance issues due to the number of security rules present?

bgirdner — Wed, 10 Dec 2014 22:33:59 GMT

I was thinking about writing very specific security rules for around 15 hosts. The rules would essentially whitelist traffic by destination ips and application. I am somewhat concerned that adding this many additional rules could potentially slow traffic down an appreciable amount for traffic that would match on rules below these.

Has anyone run into issues with performance due to too many security rules? I was able to find this post but not much else on the topic - Slow Performanced Based on Order of ACL Rules

Re: Has anyone been able to correlate performance issues due to the number of security rules present?

Dz3015 — Thu, 11 Dec 2014 14:10:46 GMT

15 should not be an issue depending on the total rules you have, what inspection policies you have running, and which device you are using.

Just make sure you use your best practices like making sure your most used rules are higher in the policy without shadowing other rules.

The only time we have encountered a resource issue of any kind is when we had an improperly formatted Data Filter but even then we didn't notice a performance hit, just high CPU.