Standard IP ACL

A

Access Control Lists (ACLs) are used in networking devices, such as routers and switches, to filter and control the traffic that is allowed to pass through them. There are two main types of ACLs: Standard and Extended.

Standard ACLs are used to filter traffic based on the source IP address of the packet. They are numbered from 1 to 99 and from 1300 to 1999. The standard IP ACL is represented by option A.

Option A:

access-list 50 deny 192.168.1.1 0.0.0.255

This command creates an access control list numbered 50 that denies any traffic with a source IP address of 192.168.1.1. The 0.0.0.255 wildcard mask means that the ACL will match any address in the range of 192.168.1.0 to 192.168.1.255.

Option B:

access-list 110 permit ip any any

This command creates an access control list numbered 110 that permits any traffic from any source IP address to any destination IP address. This is an example of an extended IP ACL, which can filter traffic based on a variety of factors, including protocol type, source and destination IP addresses, and port numbers.

Option C:

access-list 2500 deny tcp any host 192.168.1.1 eq 22

This command creates an extended IP ACL numbered 2500 that denies any TCP traffic from any source IP address to the IP address 192.168.1.1 on port 22 (which is used for SSH). This ACL would prevent anyone from accessing the device at 192.168.1.1 via SSH.

Option D:

access-list 101 deny tcp any host 192.168.1.1

This command creates an extended IP ACL numbered 101 that denies any TCP traffic from any source IP address to the IP address 192.168.1.1. Unlike option C, this ACL does not specify a port number, so it would block all TCP traffic to that IP address.

Therefore, the correct answer to the question is option A, which represents the standard IP ACL.