🛡️ Free practice test question from: ACL rules order (Security+)

In networking, Access Control Lists (ACLs) are like a series of traffic rules that are processed in a very specific order. Here's how it works:

Sequential Processing:

→ ACLs are processed in strict order, starting with Rule #1 at the top

→ Then Rule #2, Rule #3, and so on

First Match Principle:

→ As soon as a packet matches a rule, that rule is applied

→ The router/switch stops checking further rules

→ This is why order is extremely important

Rule 1: Allow traffic from 192.168.1.0/24

Rule 2: Allow traffic from 192.168.2.0/24

Rule 3: Deny traffic from 192.168.1.100

If a packet comes from 192.168.1.100:

→ It will be ALLOWED because it matches Rule 1

→ Rule 3 will never be reached, even though it was specifically meant to deny this IP

→ This is why proper rule ordering is crucial

Best Practice Tip:

→ Always place more specific rules at the top

→ Place more general rules lower down

→ Always think about the order carefully when designing ACLs

Don't forget:
'Human error was a major contributing cause in 95% of all breaches.' — IBM Cyber Security Intelligence Index Report.