What email address or phone number would you like to use to sign in to Docs.com?
If you already have an account that you use with Office or other Microsoft services, enter it here.
Or sign in with:
Signing in allows you to download and like content, and it provides the authors analytical data about your interactions with their content.
Embed code for: 08.3 IPv4 Address Representation
Select a size
08.3 IPv4 Address Representation
9/11/2016 Cisco ELearning for ICND1 v2.0 https://ondemandelearning.cisco.com/ciscosc/icnd1#/sections/8/pages/3 1/2 IPv4 Address Representation Section 8: Understanding the TCP/IP Internet Layer Every host must be assigned a unique address to communicate on an IP network. Common IP hosts include PCs, laptops, printers, web servers, smart phones, and tablets. The IPv4 address is the most common type of address that is currently used on the Internet. IPv4 addresses are 32bit numbers that are displayed as four octets (a group of 8 bits). For example, the IP address of your computer may look something like 192.168.1.24. The dots between the numbers separate the octets. The value of each octet is between 0 and 255. IPv4 addresses are separated into two sections. The first portion is the network portion. All devices on the same logical network share a common network address. For example, let's assume that your home network uses the first three octets as the network portion and your PC has an IPv4 address of 192.168.1.24. This means that every device on your home network has an IP address that starts with 192.168.1. In this example, the last octet is what is referred to as the host portion of the IPv4 address. Every device on the network has a unique host address. Since an IP address is actually 32 bits, the network and host portions are often referred to as the "network bits" and the "host bits." In the example above, the last octet is the host portion, so the last 8 bits are called the host bits. Although the figure represents an equal number of network ID and host ID bits, this is seldom the case. To revisit the postal analogy, you can think of the network portion of the IP address as the street, city, country, and zip code (postal code) of your physical address. The 9/11/2016 Cisco ELearning for ICND1 v2.0 https://ondemandelearning.cisco.com/ciscosc/icnd1#/sections/8/pages/3 2/2 network portion of the IP address is therefore analogous to the postal service routing a letter to your street. The host portion of the IP address would be equivalent to the number of your house on the street. IP networks use the network portion of the IP address to route packets to your local network. Once a packet is received on the network, it is forwarded to the individual host based on the host ID. Just as a physical street address is necessary for the postal service to deliver mail to a home or business, IP networks use logical IP addresses to determine how to deliver data from host to host. Every host connected to the Internet has a unique 32bit IP address that identifies it. To understand how IP packets are forwarded over the network, it is necessary to first learn how IP addresses are structured. An IP address includes two distinct identifiers: Network ID Identifies the network that the host is connected to Used by routers to maintain information about reachability (routes) Host ID Identifies an individual host on the IP network Assigned by organizations to devices that communicate on an IP network Up Next: IPv4 Header Address Fields