Manual and Automatic Address Assignment
An IP address can be configured manually or assigned automatically by another device, as shown in the figure.
Manual IP Configuration
With manual configuration, the required values are entered into the device via the keyboard, typically by a network administrator. The IP address entered is referred to as a static address and is permanently assigned to that device.
Dynamic IP Configuration
Most end-user devices can be set up to receive network configuration dynamically. This enables the device to request an address from a pool of addresses assigned by a Dynamic Host Configuration Protocol (DHCP) server located within the network.
Device Names and Address Planning
As a network grows in size and complexity, it becomes increasingly important that it is well planned, logically organized and well documented, as shown in the figure.
Many organizations develop conventions for naming and addressing of computers and other end-user devices. These provide guidelines and rules that can be used by network support personnel when performing these tasks.
Computer operating systems such as Microsoft Windows allows the naming of a device such as a computer or a printer. Device names must be unique and should have a consistent format that conveys meaningful information. This can help to determine device type, function, location and sequence number based on the device name. IP addresses must also be unique to each device.
The use of logical device naming and addressing conventions that are well documented can greatly simplify the task of training, network management and can help with troubleshooting when problems arise.
Network Topologies and Representations
In a simple network consisting of a few computers, it is easy for you to visualize how all of the various components connect. As networks grow, it becomes more difficult to keep track of the location of each component, and how each is connected to the network. Wired networks require lots of cabling and network devices to provide connectivity for all network hosts. A diagram provides an easy way to understand how the devices in a large network are connected.
When networks are installed, a physical topology diagram is created to record where each host is located and how it is connected to the network. The physical topology diagram also shows where the wiring is installed and the locations of the networking devices that connect the hosts. Such a diagram uses symbols or icons to represent the different devices and connections that make up a network. The figure illustrates some of the icons used to represent network components on diagrams.
Logical Network Information
Documenting the physical connections and devices in your network will provide you with the information that you need to know when connecting new devices or finding problems with broken connectivity. But there is other information that you must have when troubleshooting network problems. This information cannot be “seen” from the physical view of the network. The device names, IP addressing, configuration information, and network designations are logical pieces of information that may change more frequently than the physical connectivity.
A diagram called a logical topology illustrates the relevant network configuration information. Figures 1 and 2 show examples of physical and logical network topologies.
Think about the devices in your home or school that access the Internet. At home, do you have devices that you can control or manage from your mobile phone or tablet? Draw a physical topology of the network at your home or in your classroom. Compare your topology with those created by your classmates.