Sunday, December 13, 2009

Hoster Strato offers IPv6

The German hoster Strato now offers IPv6 on it's Highspeed-Server products. The official communication says "IPv6 Ready (Beta)". I hope "IPv6 Ready" does mean it really does IPv6. (Remember: all current operating systems are already IPv6 Ready, but mostly IPv6 is not activated nor used :-( )

Details of the offering here:

Thursday, December 10, 2009

Silly uTorrent: "hostname not found" for IPv6-only tracker on stupid Windows Vista

uTorrent is a great graphical tool to activate Teredo IPv6 on Windows XP.

However, uTorrent on Windows Vista is quite silly: with the IPv6-only tracker, uTorrent says "hostname not found". Grrrr! And do remember: on Vista Teredo IPv6 is enabled by default, so IPv6 should work.

Probably uTorrent is using Vista's braindead name resolving, meaning: no AAAA lookups with Teredo IPv6.

Advice @ uTorrent developers: on Windows Vista, do an explicit AAAA lookup ... please!

Sunday, December 6, 2009

Improved Teredo / Miredo: three suggestions

If 6to4 can be improved (see 6rd here), why not improve Teredo / Miredo? As a happy Teredo / Miredo user, I have a few suggestions:

First: Make Teredo an ISP service, by strongly binding it to the ISP: teredo server, teredo relay and addresses from the ISP. That way, ISPs have an incentive to deploy Teredo / Miredo infrastructures: help their own customers (instead of helping random people accross the Internet). This way, we would no longer have the 2001:0: teredo addresses, but ISP addresses like 2001:888:.

Second: Change Christian Huitema's Teredo protocol so that one teredo instance on a LAN can serve as a gateway for the other device on the LAN. I think one of the things thas to change, is the teredo addressing. See here for the current addressing:

Bits 0 - 31 32 - 63 64 - 79 80 - 95 96 - 127
Length 32 bits 32 bits 16 bits 16 bits 32 bits
Description Prefix Teredo
server IPv4
Flags Obfuscated
UDP port
public IPv4
Part 2001:0000 4136:e378 8000 63bf 3fff:fdd2
Decoded cone NAT 40000

My suggestion is to swap the two right hand parts ("Obfuscated UDP Port" and "Client Public IPv4"). Goal of this swap is that the last 16 bits can be freely changed, and thus used as addresses for other devices on the LAN. I guess those addresses can be assigned via RADVD or DHCPv6. The Teredo client would thus become a IPv6 gateway. The advantage is that devices on the LAN that can do simple IPv6 but not Teredo, will now be IPv6 connected to the Internet.

Third (and this is Microsoft-Teredo-only, not Miredo): Microsoft, please enable Windows Vista (and Windows 7?) to actually *use* Teredo IPv6 in the application layer. Now, a Vista machine will have IPv6 connectivity, but typing in the web browser will result in an error; apparently Windows won't lookup or use the IPv6 name & connectivity.


Fourth: modem suppliers should specify whether their modems let pass Teredo traffic. Just like the modem suppliers tell whether their modems let VPNs pass.

6rd: improved 6to4

Rémi Després has developed "6rd" (IPv6 Rapid Deployment), which is an
improved version of 6to4: 6rd has the good things of 6to4 (easy IPv6
over IPv4 tunnel technique), but has taken care of one of the Bad
Things of 6to4: with 6rd the IPv6-over-IPv4 tunnel is completely
handled by the customer's own ISP, instead of some random unknown 6to4
gateway on the Internet. So, with 6rd you get an IPv6 from your ISP,
not a 2002: address.

IMHO, one Bad Thing of 6to4 remains in 6rd: it is not desgined to work
from behind NAT. In my experience, 6to4 might or might not work behind
NAT: It depends on the NAT device: does it handle Protocol 41 or GRE
tunnels. Brrr ...
So the best solution is the deploy 6rd / 6to4 on the NAT device
itself. So far, only Free has deployed 6rd on it's self-developed
Freebox. So the wait continues for the usual suspects: when do Thomson
Speedtouch, Zyxel, Linksys, AVM Fritzbox deploy 6rd on their DSL

Relevant URLs: (alert: in French!)