1.  What subnet mask should UNI change to and use if they want to
    have up to 50 different subnetworks in the uni.edu domain?

    Note:  UNI network address is 134.161.0.0 for the class B network.

                                                         5           6
      ANSWER:  Since 50 is between 32 and 64, i.e. 50 < 2  and 50 > 2
                  we know that 6 bits will be needed
                  to specify the SUBNETwork at UNI.

               5 bits would only allow up to a maximum of 32, which is
                  not enough, but 6 will do it, allowing up to 64 subnets.
                                                
               So the subnet mask should be 255.255.252.0 for UNI.

                11111111.11111111.11111100.00000000   n = network address
                nnnnnnnn nnnnnnnn sssssshh hhhhhhhh   s = subnet address
                -------- -------- $$$$$$== ========   h = host address bits

                          1111111                 1
                12345678 90123456 12345612 34567890   - = 16 network bits
                -------- -------- $$$$$$== ========   $ =  6 subnet bits 
                11111111.11111111.11111100.00000000   = = 10 host bits
                   255      255      252      0          ----
                                                          32 bits = 4 bytes
                   255.255.252.0 is the subnet mask.

2.  How many computers could be on each subnet for UNI, given the above
    subnet mask that you developed?
                                            10
               10 bits give ONE K or 1K or 2   or 1,024 different 
                  computer or host addresses, for EACH one of the 
                  up to 64 different subnetworks.

3.  Answer questions #1 and #2 for UNI wanting to have up to 300 different
    subnets here in the uni.edu domain.

    ANSWERS:                                                 8 
                    Since 300 > 256, 8 bits is NOT ENOUGH.  2  < 300...
      Clearly, EIGHT IS NOT ENOUGH...  So shall we try 9?
                    
           9        Let's try NINE bits.  Wonderful!  512 > 300, 
      and 2  > 300, so NINE bits would give us the capability to 
      specify up to 512 different subnetworks, which is MORE THAN ENOUGH!

     Subnet mask would be 255.255.255.128.0, which is 

                          11111111.11111111.11111111.10000000
                          nnnnnnnn nnnnnnnn ssssssss shhhhhhh
                            255       255      255     128             
                          7
      How many computer? 2 or 128 computers can be h for hosts,
      on each one of the up to 512 subnetworks.  You have 7 bits
      to use to specify a host.
                                   0000000 = 0
                                   0000001 = 1        There are a total 
                                   0000010 = 2        of 128 different
                                   0000011 = 3        7 "letter" words
                                    ...               using the binary
                                   1111100 = 124      alphabet or 0 and 1.
                                   1111101 = 125
                                   1111110 = 126
                                   1111111 = 127

4.  Suppose that the subnet mask for the middleearth.com domain is:

    255.255.240.0

    Group all of the following IP numbers for the named computers
       into groups that are on the same subnet.

    144.154.31.44    Merry.middleearth.com
    144.154.16.2     Aragorn.middleearth.com 
    144.154.16.3     Gimli.middleearth.com
    144.154.220.111  Frodo.middleearth.com
    144.154.100.111  Bifur.middleearth.com
    144.154.213.111  Bilbo.middleearth.com
    144.154.125.111  Bofur.middleearth.com
    144.154.223.111  Gollum.middleearth.com
    144.154.111.111  Strider.middleearth.com
    144.154.208.222  Gandalf.middleearth.com
    144.154.16.4     Legolas.middleearth.com
    144.154.17.4     Samwise.middleearth.com
    144.154.19.4     Boromir.middleearth.com
    144.154.244.244  Sauron.middleearth.com

    You can just mention the computer name when you do the grouping,
    and avoid writing the .middleearth.com every time.