Routing Fundamentals

Reserved IP Address

Below are all the IP address reserved to be private, loopback, link-local or unspecified.

IPv4 address ranges:
- 10.0.0.0 - 10.255.255.255
- 172.16.0.0 - 172.31.255.255
- 192.168.0.0 - 192.168.255.255
IPv6 addresses range - fd00::/8

For these addresses:

The IP address range/address:

For these addresses:

The IP address range/address:

For these addresses:

Used in the absence of DHCP or static addresses
Can only communicate within its own network segment
Routers will not forward packets from a loopback address
Uses Address Resolution Protocol (ARP) to ensure that the desired IP address is not in use
IPv6 requires a link-local address even if a routable address has been assigned

Types of networks:

Personal Area Network (PAN): Smallest and simplest network type. Generally consists of one or more people connected through a single device.
Local Area Network (LAN): One of the most common network types. Local Area Networks consists of multiple computers and devices that are connected at a single site. These networks facilitate communication between devices and shared resources such as storage.
Metropolitan Area Network (MAN): This type of network is spread across a small area or region, such as a city or college campus. A MAN is a much more complex network and can be used to connect multiple LANs. The administration of a MAN may be handled by individuals or a company (ie ISP).
Wide Area Network (WAN): A WAN is a network that spans a large geographical area. WANs are used to connect multiple LANs over huge distances - the greatest example is the internet. LANs connect to a WAN via a router, which permits the use of private IP addresses on the LAN and a public-facing address (or addresses) on the WAN. This is all made possible by Network Address Translation (NAT).