Which extended ACL entry command option matches all ports except the specified number?

Which extended ACL entry command option matches all ports except the specified number?

• A. eq port-num
• B. gt port-num
• C. neq port-num
• D. lt port-num

Answer: (C)

The command option that matches all ports except the specified number is "neq port-num." This command's purpose is to deny or permit traffic that does not equal the specified port number. The "neq" stands for "not equal," making it particularly useful for scenarios where you want to allow or deny access based on all other ports while excluding one specific port, enhancing the granularity of access control lists (ACLs). In the context of extended ACLs, this allows network engineers to create more specific rules tailored to traffic management and security policies. For example, if an engineer wanted to allow traffic from all ports except for port 80, which is typically used for HTTP, using "neq port 80" would achieve that goal. The other command options function differently. The "eq port-num" command would match only traffic on the specified port number. The "gt port-num" command would match traffic on ports greater than the specified number, and "lt port-num" would match traffic on ports less than the specified number. Each of these options is useful in specific situations but does not meet the requirement of excluding a particular port number.

The command option that matches all ports except the specified number is "neq port-num." This command's purpose is to deny or permit traffic that does not equal the specified port number. The "neq" stands for "not equal," making it particularly useful for scenarios where you want to allow or deny access based on all other ports while excluding one specific port, enhancing the granularity of access control lists (ACLs).

In the context of extended ACLs, this allows network engineers to create more specific rules tailored to traffic management and security policies. For example, if an engineer wanted to allow traffic from all ports except for port 80, which is typically used for HTTP, using "neq port 80" would achieve that goal.

The other command options function differently. The "eq port-num" command would match only traffic on the specified port number. The "gt port-num" command would match traffic on ports greater than the specified number, and "lt port-num" would match traffic on ports less than the specified number. Each of these options is useful in specific situations but does not meet the requirement of excluding a particular port number.