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!

The whole site in one document for easy reference!
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 Control Message Protocol (ICMP/ICMPv4 and ICMPv6)
                9  ICMP Message Types and Formats
                     9  ICMP Version 6 (ICMPv6) Informational Message Types and Formats

Previous Topic/Section
ICMPv6 Redirect Messages
Previous Page
Pages in Current Topic/Section
1
2
Next Page
ICMPv6 Informational Message Options
Next Topic/Section

ICMPv6 Router Renumbering Messages
(Page 1 of 2)

One of the more interesting decisions made in IPv6 was the selection of a very large 128-bit address size. This provides an address space far larger than what humans are ever likely to need—and probably larger than was needed for IPv6, strictly speaking. What this wealth of bits provides is the flexibility to assign meaning to different bits in the address structure. This in turn serves as the basis for important features such as the autoconfiguration and automated renumbering of IPv6 addresses.

The renumbering feature in IPv6 is of particular interest to network administrators, since it has the potential to make large network migrations and merges much simpler. In August 2000, the IETF published RFC 2894, Router Renumbering for IPv6, which describes a similar technique to allow routers in an autonomous system to be renumbered, by giving them new prefixes (network identifiers).

Router renumbering is actually a fairly simple process—especially if we avoid the gory details, which is exactly what I intend to do. A network administrator uses a device on the internetwork to generate one or more Router Renumbering Command messages. These messages provide a list of prefixes of routers that are to be renumbered. Each router processes these messages to see if the addresses on any of their interfaces match the specified prefixes. If so, they change the matched prefixes to the new ones specified in the message. Additional information is also included in the Router Renumbering Command as appropriate to control how and when the renumbering is done.

If the Command message requests it, each router processing the message will respond with a Router Renumbering Result message. This message serves as feedback to let the originator of the Command know whether the renumbering was successful, and what changes, if any, were made.

The router renumbering standard also defines a few important management features. Many of these reflect the great power of something that can mass-renumber routers—and hence, the potential for such power to be abused. It is possible to send commands in a “test mode”, where they are processed but the renumbering not actually executed. Messages include a sequence number to guard against replay attacks, and a special Sequence Number Reset message can be used to reset the sequence number information routers have previously stored. For added security, the standard specifies that messages be authenticated and identity-checked.


Previous Topic/Section
ICMPv6 Redirect Messages
Previous Page
Pages in Current Topic/Section
1
2
Next Page
ICMPv6 Informational Message Options
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.