Skip to main content

Link-local IPv6 addresses calculation from System MAC Address

Link-local IPv6 addresses are used as part of the IPv6 network auto-configuration process. Instead of getting an address via DHCP, a NIC will hop on the network with a link-local IPv6 address and with this will have to ability to do further configuration automatically (soliciting neighbors, router, et cetera).

  1. This link-local IPv6 is infered from the NIC’s mac address.
  2.  A mac address is 48 bits, an IPv6 address is 128 bits. Here’s the conversion process step by step:
  3. take the mac address: for example 52:74:f2:b1:a8:7f
  4. throw ff:fe in the middle: 52:74:f2:ff:fe:b1:a8:7f
  5. reformat to IPv6 notation 5274:f2ff:feb1:a87f
  6. convert the first octet from hexadecimal to binary: 52 -> 01010010
  7. invert the bit at position 6 (counting from 0): 01010010 -> 01010000
  8. convert octet back to hexadecimal: 01010000 -> 50
  9. replace first octet with newly calculated one: 5074:f2ff:feb1:a87f
  10. prepend the link-local prefix: fe80::5074:f2ff:feb1:a87f

done!

Comments

Post a Comment

Popular posts from this blog

Bridging Ethernet Connections - Ubuntu/Fedora

Installing bridge-utils Adept Search for bridge-utils and choose the drop-down arrow on the left. Choose "request install". Konsole: Enter this into Konsole: sudo apt-get update sudo apt-get install bridge-utils If you use sudo -i and enter your password, then you will not have to use sudo before each command. It may also save you some typing in the future. Setting up the Bridge Ensure that both (or all) of your interfaces are installed and enabled. If they are then you may proceed at this point. For a few moments, if your computer is connected to the internet then it will be disconnected until a certain point is reached. Open Konsole and use the following commands. Note that when interfaces are referenced, they refer to device names assigned by linux such as "eth0" and "eth1". Also note that myBridge is the name of the bridge that you wish to have. This can be anything, but a simple name like bridge0 or bridge1 is s...
Post a Comment
Read more

Microsoft Active Directory

> What Intrasite and Intersite Replication? Intrasite is the replication within the same site & intersite the replication between sites. > What is lost & found folder in ADS? It’s the folder where you can find the objects missed due to conflict. Ex: you created a user in OU which is deleted in other DC & when replication happed ADS didn’t find the OU then it will put that in Lost & Found Folder. > What is Garbage collection? Garbage collection is the process of the online defragmentation of active directory. It happens every 12 Hours. > What System State data contains? Contains Startup files, Registry Com + Registration Database Memory Page file System files AD information Cluster Service information SYSVOL Folder >What is the difference between Windows 2000 Active Directory and Windows 2003 Active Directory? Is there any difference in 2000 Group Polices and 2003 Group Polices? What is meant by ADS and ADS ser...
Post a Comment
Read more

What are the few major differences between 2003,2008 & 2012

2003-IIS 6.0 2008- IIS 7.0 2008R2- IIS-7.5 2012-IIS 8 ---------------------- 2003-32 AND 64 BIT AVAILABLE 2008-32AND 64BIT AVAILABLE 2008R2- ONLY 64BIT AVAILABLE 2012 - ONLY 64 BIT AVAILABLE ------------------------------------------ 2003 KERNAL VER. -5.2 2008 KERNEL-6.0 2008 R2-6.1 2012-6.2 ------------------------------------------ 2003- IE VERSION 6.0 2008- IE VERSION 7.0 2008 R2 IE VERSION 8.0 2012 IE VERSION 10.0 2012 R2 IE VERSION 11.0 ----------------------- 2003- AD ADMINISTRATIVE CENTER NOT AVAILABLE 2008- NOT AVAILABLE 2008 R2- AVAILABLE 2012- AVAILABLE -------------------------------------
Post a Comment
Read more