From the course: Cisco Networking Foundations: Wireless Networks, Services, Security, and Virtualization

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Extended numbered ACL theory

Extended numbered ACL theory

From the course: Cisco Networking Foundations: Wireless Networks, Services, Security, and Virtualization

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Extended numbered ACL theory

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- [Instructor] Now, that we've discussed the theory and configuration of standard numbered ACLs, in this video, let's consider extended numbered ACLs and whether we're talking about numbered or named, an extended ACL can match both source IP address information and destination IP address information. And recall that destination IP address information, that was something that we could not specify with a standard ACL. Something else we could not specify with the standard ACL was a specific protocol to permit or deny, but with an extended ACL, we can permit or deny specific protocols within the IP protocol suite. For example, we might want to deny Telnet. We could deny TCP Port 23. We might want to deny TCP Port 80, which is HTTP, both HTTP and Telnet not being very secure protocols, but we might permit HTTPS, the secure version of HTTP which is TCP Port 443. And when we're creating an extended ACL, if it's numbered, it needs to…

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