Step 2: Configure DHCP reservations for network devices

The ensuing “ping fests” will be much more palatable if each networked device has its own, unchanging IP address. This is done through the magic of Dynamic Host Configuration Protocol (DHCP) IP address reservation. Having a unique IP for each device can also be used to limit access to Apache and BIND, more on this later.

1. Record the Media Access Control (MAC) addresses of each networked device

   A DHCP reservation requires the Media Access Control (MAC) address of each device connected to the network. Since a MAC address uniquely identifies a network adapter, it’s quite sensitive. To this end I’m using 00-00-00-00-00-00 to represent MAC addresses in all examples. You will need to substitute your own devices’ MAC addresses.

   1. To find the MAC address of a Windows device, at the command prompt, type:

      C:\>ipconfig /all

      Press Enter.

      Under the Ethernet adapter Local Area Connection heading, look for a line like this:

      Physical Address. . . . . . . . . : 00-00-00-00-00-00

      The MAC address is the six pairs of hexadecimal digits separated by dashes.

   2. On a Linux/Mac device, open a terminal emulator, type:

      $ ifconfig

      Press Enter.

      After you calm down from exposure to even more delicious information, look for a line like this:

      wlan0 Link encap:Ethernet  HWaddr 00:00:00:00:00:00

      The MAC address is the six pairs of hexadecimal digits separated by colons. In this example, wlan0 represents a wireless network adapter.

   3. To find the MAC address of your mobile device(s), you may want query your favorite search engine.

2. Configure DHCP IP Reservations

   1. Log in to your router’s Admin panel
   2. Click Setup
   3. Click Network Settings
   4. Under the DHCP Server Settings heading, check the Enable DHCP Server check box (it may be selected by default), click the Save Settings button
      
   5. Under the Add DHCP Reservations heading, check the Enable checkbox
      

   6. Add the following information for each device requiring a reserved IP address. Do not add the development server’s static IP. Here’s an example:

      Computer Name:	Laptop
      IP Address:	192.168.0.197	(must be within router’s DHCP address range)
      MAC Address:	00:00:00:00:00:00	(use your device’s real MAC Address)

      Click the Save button after each entry.

      

      Completed DHCP reservations

Step 3: Limit network access with MAC filtering

This step is optional. Some consider that MAC address filtering offers little more than a false sense of security—Why you shouldn’t use MAC filtering… Defense in depth, or simply rearranging the deck chairs on the Titanic, you decide. If you want to give it a go, here’s how:

Configuring a router’s MAC address filtering

1. Log in to the router’s admin panel. Click Advanced, click Network Filter.
2. Under MAC Filtering Rules, select Turn MAC Filtering ON and ALLOW computers listed to access the network from the drop down list

3. Add the (real) MAC Address of each device. If the device has been assigned a DHCP reserved IP address, you can simply select the device from the DHCP Client List drop-down menu. Click Save Settings

   

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