To create an access control list (ACL) on a Cisco Adaptive Security Appliance (ASA) firewall, you need to use the access-list command followed by the name of the ACL, the action (permit or deny), the protocol, the source address and mask, and the destination address and mask. For example, to permit HTTP traffic from the inside network 192.168.1.0/24 to any destination on the internet, you can use this command:
access-list inside_access_in permit tcp 192.168.1.0 255.255.255.0 any eq www
This command creates an ACL named inside_access_in that permits TCP traffic from the source network 192.168.1.0/24 to any destination with the destination port equal to 80 (www). The eq keyword is used to specify the port number or name. You can also use the range keyword to specify a range of ports.
To apply the ACL to an interface, you need to use the access-group command followed by the name of the ACL and the direction (in or out). For example, to apply the ACL to the inside interface in the inbound direction, you can use this command:
access-group inside_access_in in interface inside
This command applies the ACL inside_access_in to the interface named inside in the inbound direction. This means that the ACL will filter the traffic that enters the firewall through the inside interface.
Option D is the only option that matches the syntax of the access-list command for the ASA firewall. Option A is incorrect because it uses the ip keyword instead of the tcp keyword. Option B is incorrect because it uses the any keyword for both the source and destination addresses. Option C is incorrect because it uses the host keyword for the source address, which is not valid for a network address.
[References:, Configure ASA Access Control List for Various Scenarios, Cisco ASA Access Lists Concepts and Configuration, How to Configure Access Control Lists (ACL) on Cisco ASA 5500 Firewalls, , , ]
