If you have a valid IPv6 prefix why use 6to4 addreses at all? Why not just deprecate 6to4 and move to IPv6 addresses directly?
thanks /jim > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Fredrik Tolf > Sent: Wednesday, March 16, 2005 6:38 AM > To: Michael Banta > Cc: [EMAIL PROTECTED]; users@ipv6.org > Subject: Re: 6to4 question > > On Wed, 2005-03-16 at 04:41 -0500, Michael Banta wrote: > > I am aware of a full ip address, just figured I would spare > you the full > > address since it is not pertenant to the question. > > > > I keep reading that with 6to4 addresses, they are supposed > to start with > > 2002: prefixes so that autoconfiguration can take place > with the clients. > > 6to4 address are something quite different from a block > provided through > a tunnel. a 2001 address is a "real" IPv6 address -- that is, > a part of > the IPv6 Internet with no IPv4 dependencies. > > 6to4 addresses (i.e. those starting with 2002), on the other hand, are > part of the IPv4-to-IPv6 migration plan. If you have a globally > aggregatable IPv4 address (i.e. an IPv4 address that anyone > on the IPv4 > internet can send packets to, such as _not_ a part of the > 192.168.0.0/24 > blocks), you are, with 6to4, automatically given a /48 IPv6 subnet. > > I know I haven't really explained this very well at this > point, so I'll > try with an example. I'm using 6to4. I have a static IPv4 address, > 82.182.133.20. Written in hexadecimal, that is 52.b6.85.14. > Using that, > I can construct my automatic 6to4 subnet: > 2002:52b6:8414::/48. I, too am > using a Linux router with radvd, and the computer I'm typing this from > has gotten the address2002:52b6:8514:200:20c:76ff:fe3b:a3f4. The nice > thing with this is that I need no tunnel provider. The bad > thing is, of > course, that it depends on IPv4. > > The way 6to4 works is that when my router detects an outgoing IPv6 > packet, it first checks the destination address. If it starts > with 2002, > it rolls the packet inside an IPv4 packet, checks bits 16 > through 48 in > the destination address, and put those in the IPv4 destination address > field. For example, when communicating with my friend, who also uses > 6to4 and has the IPv4 address 213.132.111.101, I send a packet to her > IPv6 address, 2002:d584:6f65::1. My router extracts > d584:6f65, which is > 213.132.111.101 in hexadecimal, and puts that in the IPv4 packet's > destination address field, puts the IPv6 packet as the IPv4 > payload, and > sends the packet. When her computer picks it up, it unwraps the IPv6 > packet and uses it. > When communicating with a non-6to4 address, my router sends it, again > wrapped in an IPv4 packet, to a IPv4-to-IPv6 router on the Internet. > Many ISPs support the anycast address 192.88.99.1, which always means > "the closest IPv4-to-IPv6 router". When a non-6to4 host wishes to send > v6 packets to me, it just sends them normally and the IPv6 Internet > backbone will route them to the closest IPv6-to-IPv4 router, > which will > wrap their package in an IPv4 packet, check the IPv6 > destination address > (2002:52b6:8514:X) and calculate the proper IPv4 destination > address (my > 82.182.133.20 address) from that, and send it to me over > IPv4. My router > will then unwrap it when it gets it, and forward it over my internal > IPv6 network. > > So as you see, 6to4 addresses are something quite different from the > 2001::/48 block that you got from your tunnel provider. > > > The /48 was given to me by the provider. I am aware of the > addresses > > construction, just can't figure out how to get the clients > to connect > > through the router. > > I still don't really understand what your actual problem is, after all > this. > > Hope this helps. > Fredrik Tolf > > --------------------------------------------------------------------- > The IPv6 Users Mailing List > Unsubscribe by sending "unsubscribe users" to [EMAIL PROTECTED] > --------------------------------------------------------------------- The IPv6 Users Mailing List Unsubscribe by sending "unsubscribe users" to [EMAIL PROTECTED]
