2 Replies Latest reply: Sep 1, 2010 3:07 PM by FernandoDias RSS

    VLSM Overlap doubt

    FernandoDias

      Hi All,

       

      I am studying for my CCNA Certification and I have a doubt about VLSM.

       

      Take a look at the question:

       

      R1 has configured interface Fa0/0 with the ip address 10.5.48.1 255.255.240.0
      command. Which of the following subnets, when configured on another interface on
      R1, would not be considered to be an overlapping VLSM subnet?
      a. 10.5.0.0 255.255.240.0
      b. 10.4.0.0 255.254.0.0
      c. 10.5.32.0 255.255.224.0
      d. 10.5.0.0 255.255.128.0

       

      In the book, the answer to this question is as follows:

       

      C and D. Subnet 10.5.0.0 255.255.240.0 implies range 10.5.0.0–10.5.15.255, which
      does not overlap. 10.4.0.0 255.254.0.0 implies range 10.4.0.0–10.5.255.255, which
      does overlap. 10.5.32.0 255.255.224.0 implies range 10.5.32.0–10.5.63.255, which
      does overlap. 10.5.0.0 255.255.128.0 implies range 10.5.0.0– 10.5.127.255, which
      does overlap.

       

      I thought the right answer was letter A. Am I wrong? Or I didnt understand the question?

      I am using ICND2, Wendell Odom, PDF VERSION.

       

      Best Regards,

       

      Fernando