PC1 has an IP address of 10115 and PC2 has an IP address of

PC1 has an IP address of 10.1.1.5, and PC2 has an IP address of 10.1.2.5. Which of the following statements is true regarding these two systems?

A. If classful addressing is used, both PCs always belong to the same network ID.

B. If classful addressing is used, both PCs do not belong to the same network ID.

C. If classless addressing is allowed, both PCs may be on the same network ID.

D. If classless addressing is allowed, both PCs are never on the same network ID.

Solution

A and C are correct. Classful addressing means the addresses always stay within their class. Since both addresses begin with 10, they are Class A addresses in the same network. If classless addressing is allowed, the class can be subnetted. If the 10.0.0.0 is properly subnetted, both devices could be on the same network.

B and D are incorrect. B is not correct because classful addressing places both devices on the same network (10.0.0.0). D is not correct because subnetting could allow both to be on the same network.