Class B

hassantalal785hassantalal785 Posts: 47Member ■■□□□□□□□□
In Todd Lamlle's book it is written "Using a /16 means you are not subnetting with Class B, but it is a mask you can use." i can't understand this as /16 is default subnet of Class B .


  • NetworkVeteranNetworkVeteran Posts: 2,338Member ■■■■■■■■□□
    From Wikipedia--
    Wikipedia wrote:
    A subnetwork, or subnet, is a logically visible subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.

    If you're given the class B network, and you assign it to an interface directly--

    interface Ethernet0
    ip address
    no shutdown

    The mask is--nnnnnnnn.nnnnnnnn.hhhhhhhh.hhhhhhhh. It has 16 network bits, 0 subnet bits, and 16 host bits. You have not performed subnetting. You haven't divided the network into subnets.

    If you instead do like so--

    interface Ethernet0
    ip address
    no shutdown

    The mask looks like so--nnnnnnnn.nnnnnnnn.ssssssss.hhhhhhhh. It has 16 network bits, 8 subnet bits, and 8 host bits. You have now performed subnetting, by dividing the network into subnets. :)
  • hassantalal785hassantalal785 Posts: 47Member ■■□□□□□□□□
    Awesome explanation.Thanks
Sign In or Register to comment.