lancehank

Q: Two IPv6 Addresses

I am quite experienced with networking but this is just mind boggling for me. I have a MacBook Pro Retina so it only has wifi built in. But when I go through "network Preferences" then click "Advanced" and under the TCP/IP tab it shows I have 2 version 6 addresses, both completely different from each other. I recently bought a Thunderbolt to Ethernet adapter and it also shows 2 addresses that differ from the ones shown on wifi. I've been studying networking this quarter and we recently went over IPv6 but cannot for the life of me find out why my computer has two.

 

Any help is much appreciated. Thank you in advanced.

MacBook, Mac OS X (10.7), 2008 Aluminum Unibody

Posted on Aug 1, 2013 10:23 AM

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Q: Two IPv6 Addresses

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  • by ByronJones,

    ByronJones ByronJones Feb 7, 2015 8:44 AM in response to lancehank
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    Feb 7, 2015 8:44 AM in response to lancehank

    IPv6 automatically creates several addresses for each network connection. While IPv4 addresses were often a 1:1 relationship with interfaces, that isn't the case with IPv6 addresses, which are always 1:many. There are "link local" addresses starting with fe80: and other addresses that can be autoconfigured.  It is important to understand that ipv6 tries to make address configuration transparent to the user as much as possible.  Manual IP addresses are essentially deprecated, and even DHCP servers are largely unnecessary.  IPv6 routers should make announcements with the information that endpoint devices need to configure themselves.  The local ipv6 addresses are handled automatically.  Assuming that your ISP and router are IPv6 enabled, the "real" ipv6 addresses which support communication over the Internet should be autoconfigured as well.