Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Read offline with no ads or diagram watermarks!
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)
      9  TCP/IP Internet Layer (OSI Network Layer) Protocols
           9  Internet Protocol (IP/IPv4, IPng/IPv6) and IP-Related Protocols (IP NAT, IPSec, Mobile IP)
                9  Internet Protocol Mobility Support (Mobile IP)

Previous Topic/Section
Mobile IP Addressing: Home and "Care-Of" Addresses
Previous Page
Pages in Current Topic/Section
1
2345
Next Page
Mobile IP Home Agent Registration and Registration Messages
Next Topic/Section

Mobile IP Agent Discovery, and Agent Advertisement and Solicitation Messages
(Page 1 of 5)

When a mobile node is first turned on, it cannot assume that it is still “at home” the way normal IP devices do. It must first determine where it is, and if it is not at home, begin the process of setting up datagram forwarding from its home network. This process is accomplished by communicating with a local router serving as an agent, through the process called agent discovery.

Agent Discovery Process

Agent discovery encompasses the first three steps in the simplified five-step Mobile IP operational summary I gave in the topic on general operation. The main goals of agent discovery include the following:

  • Agent/Node Communication: Agent discovery is the method by which a mobile node first establishes contact with an agent on the local network to which it is attached. Messages are sent from the agent to the node containing important information about the agent; a message can also be sent from the node to the agent asking for this information to be sent.

  • Orientation: The node uses the agent discovery process to determine where it is. Specifically, it learns whether it is on its home network or a foreign network by identifying the agent that sends it messages.

  • Care-Of Address Assignment: The agent discovery process is the method used to tell a mobile node the care-of address it should use, when foreign agent care-of addressing is used.

Mobile IP agents are routers that have been given additional programming to make them “Mobile IP aware”. The communication between a mobile node and the agent on its local network is basically the same as the normal communication required between a device on an IP network and its local router, except more information needs to be sent when the router is an agent.


Previous Topic/Section
Mobile IP Addressing: Home and "Care-Of" Addresses
Previous Page
Pages in Current Topic/Section
1
2345
Next Page
Mobile IP Home Agent Registration and Registration Messages
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.