U nderstanding IPv4 Addresses
An IP Address is a logical address used in order to
uniquely identify a device on an IP network.
- It’s a Network Layer Address
- There are Two Versions:
- IP version 4 (IPv4)
- IP version 6 (IPv6)
- This course focuses on IPv4 Addresses
An IP Address is made up of 32 binary bits, which can be divided into a network portion and a host portion with the help of a subnet mask.
- The 32 binary bits are broken into four octets (1 octet = 8 bits).
- Each octet is converted to decimal and separated by a period (dot).
- For this reason, an IP address is said to be expressed in dotted decimal format.
An IP address is broken down into two parts:
- Uniquely identifies each network
- Your Street Name: 7682 Wilshire Drive
- Uniquely identifies each machine on a network
- Your House Address: 4682 Wilshire Drive
Network Address + Host Address = IP Address
- 4682 + Wilshire Drive = 4682 Wilshire Drive
Each device on a network is assigned an IP address, subnet mask and default gateway:
- IP Address: Unique logical address assigned to each device on a network.
- Subnet mask: Used by the device to determine what subnet it’s on.
- Default Gateway: The router’s IP address that allows the device to communicate outside it’s local subnet.