Upcoming Events

Executive conference

Cloud Connect March 16-18

Comprehensive thought leadership for executives, IT professionals and developers. Topics include: the ROI, cost and economics of on-demand computing; Migration strategies to move from on-premise to cloud-based IT; Vertical cloud specialization, tailoring features and architectures to specific applications, industries, and customer ecosystems

More Events »

Subscribe to Newsletter

  • Keep up with all of the latest news and analysis on the fast-moving IT industry with Network Computing newsletters.
Sign Up



IP Routing Primer: Part One

November 6, 2000
by Peter Morrissey

Table of Contents

 

In many ways, the task of a router is very simple. It must look at the destination address of an IP packet and then forward the packet to another router or to a directly connected host. However, if you've ever attempted to get two devices to communicate on an IP network, you know that it doesn't always work.

In this Network Design Manual article we'll show you the steps involved in getting a packet from Point A to Point B on an IP network. We'll talk about the settings that are necessary on a host to communicate on a routed network and what they really mean. Once you understand this, you'll be able to ask the right questions when things don't go as expected and even do a little bit of your own troubleshooting.

Anatomy of an IP Address

When one host has data to send to another host, it sends it to its local IP process, which builds an IP packet for transmission on the network. The packet has a header, which includes the destination IP address as well as the source address of the local host. The destination and source IP addresses stay with the data until it arrives at the host so that all the routers it traverses know in what direction to send it. The source address provides the destination host with an address to which it can send its response.

To understand how this happens requires a deeper knowledge of the IP address. It's obvious that an IP address consists of four separate numbers, separated by dots. Each number represents one byte worth of data, limiting it to a range of 256 possible values, commonly represented as decimal values from 0 to 255 or binary values from 00000000-11111111.

One thing that is not so obvious is that each IP address is always divided into two sections. The first section always delineates the network address, or subnet. This is the part routers are primarily concerned with. The second section, combined with the first section forms a unique node address. The subnet mask is configured to tell the host or client which part is the network address and which part is the node address.

PAGE: 1 I 2 I 3 I I NEXT PAGE

 

Best of the Web

Data deduplication: Declawing the clones

Data deduplication is emerging as a critically important new arrow in the storage administrator's quiver to answer hard questions about the increasing problem in storage growth costs.

Quick Read

Compression, Encryption, Deduplication, and Replication: Strange Bedfellows

One of the great ironies of storage technology is the inverse relationship between efficiency and security: Adding performance or reducing storage requirements almost always results in reducing the confidentiality, integrity, or availability of a system.

Quick Read

WAN Optimization Whitelists and Blacklists

Optimization is a fantastic way of saving money and creating really happy customers at the same time, but it doesn't work flawlessly for all applications.

Quick Read

WAN Optimization as a Managed Service: It's Not About the Cost

This insight examines how organizations outsourcing their WAN optimization initiatives to a third-party go about achieving their goals for application performance, reducing operational costs, and streamlining enterprise infrastructure.

Quick Read

  Sponsored Links

Premium Content

Next Generation Data Center, Delivered, November 17th
NWC


Salary

Video