Manage Learn to apply best practices and optimize your operations.

IP Networking

Looking for something else?

Unfortunately, the huge growth of home and business computing was never anticipated. IPv6 has several trillion available addresses which should last a few years into the future.

IP addresses are broken into classes. Classes were used when IP addresses were first invented. Depending upon how large your organization was, depended upon which class of IP address you were given.

IN THE REAL WORLD:
IP addresses are assigned by a group called the INIA. You can also buy then from an ISP who has in turn bought a block form the INIA.

Class B addresses were reserved for large organisations who needed a lot of host numbers but not as many as the larger ones. Unfortunately, when a class B address was assigned to an organisation, it still resulted in thousands of wasted host numbers. Class B addresses have to have the first two binary columns reserved with a 1 and a 0 next to it. So the first network number is 128. The last available class B network number is 191 (add the values). For Class B addresses we use the first two octets for the network address. So for the address 130.24.5.2. 130.24 is the network number and 5.2 is a host on that network. The rule is still that the first number you see though will always be between 128 and 191. If we use the powers of two rule for the first two octets we will see that we can have a possible 16384 networks. 2^16= 16384 We are not allowed to use the first two bits of the first octet because they are reserved for showing the 10 value remember? So this leaves us with 6+8 digits. 2^14 gives us 16384 networks. We have the full two octets to use for hosts so 8+8 gives us 2^16 = 65534 hosts per class B network.

Theses were originally reserved for any other organization who was not large enough to warrant having a class A or B address. A class C address has the first three bits reserved so the networking device can recognize it. The first three bits show as 110. So the first network number is 192. And the last is 223. An example of a class C address is 200.2.1.4. 200.2.1 is the network address and .4 is a host on that network. So we can see that there are lots of available network numbers to assign to companies however, we have a limited amount of numbers free to use on our networks. For networks we have to take the 011 from the first octet giving us 5+8+8= 21. 2^21 = 2097152 For the hosts we have 2^8 giving us 255. We will see in a short while that not every single number can be used because we need to reserve some for a special purpose.

Class D and Class E Addresses

Class D addresses are reserved for multicast traffic and cannot be used on your network. Multicast traffic is traffic send to multiple hosts using one IP address. A live webcast of a rock concert would be an example of multicasting. Class E addresses are reserved for experimental use only.

Summary

10

190

220

So far we can condense what we know to: Class A - first bit set to 0. Address range 1-126 (127 is reserved for testing) Network.Host.Host.Host Class B - first bits set to 10. Address range 128-191 Network.Network.Host.Host Class C - first bits set to 110. Address range 192-223 Network.Network.Network.Host We only need to look at the number in the first octet to recognize which class address we are dealing with. .1.2.1 = Class A .2.3.4 = Class B .3.4.2 = Class C FIG 4.1 IP Addressing Classes Summarized

The people at FreeSkills.com were nice enough to share one of their many free tutorials with us in order to make "IP Addressing" available to SearchNetworking.com readers. FreeSkills.com has more than 400 free tutorials and many reasonably-priced courses available for different IT subjects. We recommend you stop by and visit this wonderful resource!

This was last published in August 2004

Content

Find more PRO+ content and other member only offers, here.

Start the conversation

Send me notifications when other members comment.

SearchSDN

• NFV disaggregates firewall appliance to increase scalability

A traditional firewall appliance can incorporate many services, but NFV can virtualize firewalls to offer individual services ...

• Cisco, Hyundai to add software-defined platform to vehicles

Cisco and Hyundai will release jointly developed software-defined vehicles in 2019. These connected cars will boast a Cisco-built...

• Zayo SD-WAN available as a managed or on-premises product

Zayo Group has launched an SD-WAN product. The Zayo SD-WAN is available as an on-premises or managed product. Zayo is a bandwidth...

SearchEnterpriseWAN

• How to calculate network bandwidth requirements

Figuring out how to calculate bandwidth requirements is vital to ensuring your network runs smoothly, and it's best to get the ...

• How types of noise in data communication systems affect the network

Learn about the different types of noise in data communication -- including thermal, intermodulation, cross-talk, impulse and ...

• The best VPNs for enterprise use

This slideshow highlights the best VPNs used in enterprise wide-area networks (WANs) and offers principles for designing and ...

SearchUnifiedCommunications

• Emerging technologies to fuel collaboration industry growth

Business communications is getting more contextual and intelligent, thanks to emerging technologies, such as AI and APIs. UCC ...

• How to navigate the enterprise collaboration market

When evaluating enterprise collaboration services, first look inward at your company needs. Some key collaboration criteria ...

• Businesses slow to embrace products like Samsung Flip board

Samsung hopes to heat up the tepid digital whiteboard market, but the new Samsung Flip board will face tough competition from ...

SearchMobileComputing

• A roundup of the leading EMM providers in today's market

Just as identifying the need for EMM is important, so is selecting the right vendor. Here's a rundown of leading EMM vendors and ...

• Compare the main mobile app development languages

Developing an app is all about visualizing what the users need and what they'll see in the UI. Get visual with this infographic ...

• A handy mobile app testing checklist for developers

Application testing is a necessity in the era of enterprise mobility. Define the right testing criteria and adopt the proper ...

SearchDataCenter

• Three requirements for a hybrid cloud computing deployment

As the hybrid cloud computing approach gains steam, organizations will need to pay close attention to cross-cloud connectivity ...

• Five debunked myths about SSD issues

Solid-state drives are mature now, and the technology has eclipsed hard disk drives with superior performance, manageability and ...

• Future data center trends hinge on the edge, cloud and staffing

Edge computing, colocation, cloud and IT staffing issues lead the way as industry analysts make their predictions for the future ...

SearchITChannel

• Riverbed Rise channel program reinvents partner requirements

The Riverbed Rise program will focus on partner performance, which Riverbed will measure by customer acquisitions, account ...

• Primary and secondary storage combos attract channel partners

Nontraditional storage vendors, such as ClearSky Data and Reduxio, are attracting resellers and managed service providers with ...

• Demand for cloud-enabling infrastructure soared in 2017, says IDC

IDC's latest cloud IT infrastructure market tracker shows the demand for public and private cloud-enabling servers, storage and ...

Close