IP ADDRESS
The Internet Protocol Address (or IP Address) is a unique address that computing devices such as personal computers, tablets, and smartphones use to identify itself and communicate with other devices in the IP network. Any device connected to the IP network must have a unique IP address within the network. The traditional IP Address (known as IPv4) uses a 32-bit number to represent an IP address, and it defines both network and host address. A 32-bit number is capable of providing roughly 4 billion unique numbers, and hence IPv4 addresses running out as more devices are connected to the IP network. An IP address is written in “dotted decimal” notation, which is 4 sets of numbers separated by period each set representing 8-bit number ranging from (0-255).
DIFFERENCE BETWEEN THE PRIVATE IP ADDRESS AND PUBLIC IP ADDRESS PUBLIC IP ADDRESS
A public (or external) IP address is the one that your ISP (Internet Service Provider) provides to identify your home network to the outside world. It is an IP address that is unique throughout the entire Internet. Depending on your service, you might have an IP address that never changes (a fixed, orstatic IP address). But most ISPs provide an IP address that can change from time to time (a dynamic IP address). For the vast majority of users, a dynamic IP address is fine.When you’re setting up your router, if your ISP issued you a static IP address, you enter it into your router’s settings. For a dynamic IP address, you specify DHCP in your router’s network settings. DHCP is Dynamic Host Control Protocol. It tells your router to accept whatever public IP address your ISP issues.PRIVATE IP ADDRESS Just as your network’s public IP address is issued by your ISP, your router issues private (or internal) IP addresses to each network device inside your network. This provides unique identification for devices that are within your home network, such as your computer, your Sling box, and so on.Similar to the arrangement with public IP addresses, each device on your network has its network configuration settings on DHCP, so it can accept the unique private IP address that your router issues it.These private IP addresses never leave your network, just as your public IP address is never used inside your network. The router controls all the network traffic, both within your home network and outside of it, to the Internet. It is the router’s job to make sure that data flows to and from all the correct places.
APIPA (Automatic Private IP Addressing)
The Windows function that provides DHCP auto configuration addressing. APIPA assigns a class B IP address from 169.254.0.0 to 169.254.255.255 to the client when a DHCP server is either permanently or temporarily unavailable. Designed for small non-routable networks, if a DHCP server becomes available later, the APIPA address is replaced with one from the DHCP server. For example, when a Windows Vista machine starts up, it waits only six seconds to find a DHCP server before assigning an IP from the APIPA range. It then continues to look for a DHCP server. Previous versions of Windows looked for a DHCP server for up to three minutes.
MAC ADDRESS
MAC, Media Access Control, address is a globally unique identifier assigned to network devices, and therefore it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format. The first 3-bytes are ID number of the manufacturer, which is assigned by an Internet standards body. The second 3-bytes are serial number assigned by the manufacturer.How do we find a MAC address of network device?Operating Systems support various command-line and GUI utilities to allow users to find MAC address of the system. Windows including NT, 2000, XP and 2003 support “ipconfig/all” command that displays MAC address. On a Mac OS, one can find MAC address by opening “System Preferences”, then selecting “Network”.