What are all these weird numbers in my IPconfig?
When IPv6 was first installed by default in Vista (in 2003!) lots of email went around the internal mailing lists claiming corruption of the output of ipconfig. Turns out, it was just the new 128 bits of addressing that ipv6 provides that was scaring people Ipv6 addresses are quite different looking from ipv4
There are several types of IPv6 Addresses
Link local:
Starting with fe80 (ie fe80::69ef:b63b:29c4:cde3) all machines will get at least one of these autoassigned addresses, they are similar to the 169.254.0.0 addresses assigned when a DHCP server is not available on a network.
Localhost/Loopback:
Our friend Mr loopback gets transformed from 127.0.0.1 to ::1
Teredo:
Starts with 2001: (formerly with 3ffe:831f), teredo is basically a way to tunnel ipv6 over ipv4 UDP packets. The ipv4 address and port mapping of the NAT are included in the address.More info here.
6to4:
Starts with 2002: followed by the hexadecimal formatting of the public IPv4 address
Native:
No well known prefix, the prefix is assigned by IANA similar to the allotment of ipv4 subnets. The original hope is that a form of network locality will be encoded in the addresses (ie BackboneProviderPrefix:RegionalNOC:SmallerIsp:Company) so you can determine which hosts are “closer” to you by comparing prefixes.
There are others (Sitelocal, multicast) but these are the ones you will normally see in the output from ipconfig.
Ipv6 is a very extensive set of protocols and standards (dwarfing Ipv4) that cannot be easily summarized in a blog post. I recommend the Wikipedia links as they have several good articles explaining it.
For further info: