Question 1.
a)  (i)     10.16.0.0/16
            4 bits needed for subnetting.
            Leaves 12 bits for host addressing.
            2^12 = 4096

            Subnet mask will be /20 or 255.255.240.0 (don't need to know dotted decimal notation)
        
    (ii)    Will never ask the last one (again).
            First subnet: 10.16.10.0./20
                Hosts: 10.16.0.1 --> 10.16.15.254
                Broadcast: 10.16.15.255
            Second subnet: starts from where the first left off
                Hosts: 10.16.16.1 --> 10.16.31.254
                Broadcast: 10.16.31.255

    (iii)   10.16.0.0/13
                which represents everything form 10.16.0.0 --> 10.23.0.0
b)
    - a good answer will be about page
    - write legibly
    - no competitor for DNS.
    - don't expect us to know competitors for GNS3
    - IXPs are well covered in the notes.
        - why do IXPs exist?
            - to keep internet routing as efficient and local as possible
        - what do they do?

Question 2.
a)  Reasons to use VLANs:
        - keep traffic separate
            - security
        - limit broadcast traffic


    VLAN 1 is usually reserved as the "Native VLAN"
    VLAN ID is 12 bits so maximum is 4096.
    Any valid VLAN ID and subnet is acceptable

b)  `e0` would be dot1q because it is a trunk port: tags traffic for VLANs
    `e1` would be dot1q because it is a trunk port: tags traffic for VLANs
    `e2` is an access port for the Support VLAN

    802.1q tags ethernet headers to add the VLAN ID so the packet goes to the correct VLAN.
    Also have 3 bits which define priority for the packet.