shownotes_MCM20101227

DHCP
  Stands for Dynamic Host Configuration Protocol (DHCP)
  What is an IP address?
    Internal "private" IP addresses vs public addresses
  If you have a home LAN and router then the router typically assigned the IP address and manages the leases
  If there is a problem with that management and devices end up with the same IP then the network can be effected
Static IP addresses
  Set in the client.
  Trouble that with Macs, you would need to set up "locations" if you move between private networks
DHCP Reservation
  A way to assign the same IP address to the same computer of devices from the DHCP server (router)
  Supported by Airport Express, Macs and iOS devices. Also many 3rd party routers.
Finding a client id
  You will use either the DHCP Client ID or the MAC address to assign the DHCP reservation on your router
  DHCP Client ID
    On Mac, System Preferences-->Network-->choose interface (Ethernet, AirPort, etc.)
      Click the 'Advanced…' button
      When set to 'Configure Using DHCP' in the TCP/IP tab there is a box for DHCP Client ID
      Set the ID to whatever you want, but remember it for later
    On iOS
      Settings-->General-->Network-->Select the network
      Under 'DHCP' add a 'Client ID'
  MAC Address
    Media Access Control address.
      A number consisting of six groups of two hexadecimal digits separated by a colons
    For ANY network device, or more specifically interface. Not just an Apple thing.
    On the Mac
      System Preferences-->Network-->Select the Interface
      Click on the 'Ethernet' tab
      Note the Ethernet ID
      Can also find it in the System Profiler under 'Network'-->'Locations' and looking for the 'MAC Address' value for each interface.
    On iOS
      Settings-->General-->About
      Note the 'Wi-Fi Address'
Make the reservation
  Specific instructions will vary slightly based on your network setting and router
    I use an AirPort extreme and private IPS in the 10.0.0.0 range. 192.168.0.0 and 172.16.0.0 are also possible
  In the Airport Utility
    Select the Airport and click the "Manual Setup" button
    Select the 'Internet' section
    Then click on the 'DHCP' tab
    Setting the DHCP address range (optional)
      I do this to leave part of the range open for static IPs
    You can also check your DHCP lease time here
    Section for DHCP Reservations
      Click the "+" button
      In the 'Description' enter anything you'd like to remember the reservation
      Reserve by, choose MAC Address or DHCP Client ID
      Then enter the MAC Address or Client ID depending
      Set the desired IP address. Preferably outside the range of already DHCP assigned addresses on your network, but still in the DHCP range.
      Click 'Done' and then Update to reset the Airport
    You may need to reset the device or renew the DHCp lease for it to take effect on the client.
    From this point forward on your network it should always assign that IP address to that device.