Teredo

[Greenstead]

"Sea worms" notorious for the destruction which they cause in ships' wet timbers. They inhabit long cylindrical holes, which they excavate in the wood, and usually occur in numbers, crowded together so that often only a very thin film remains between the adjacent burrows.
http://encyclopedia.jrank.org/TAV_THE/TEREDO.html

Teredo is also the name given to the windows Internet Protocol IPV6 transition technology built into Vista and XP SP2 providing any PC to talk to any other PC on the internet without the need to configure the intervening NAT routers. Since there are few IPV6 NAT routers existing to-date Teredo has the ability to tunnel thru IPV4 NAT routers by wrapping its IPV6 protocol in an IPV4 UDP packet thereby fooling existing IPV4 routers to allow it thru (more technically termed NAT translation). Each PC needs a unique PNRP name (peer name resolution protocol) which acts similar to a HOST DNS name but using PNRP servers.
:confused:
Read about it:
http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/teredo.mspx

Putting the techno-gabble aside.
You give your PC a name e.g.FredsPC, and connect to it from any other PC on the internet. No fixed IP, no NAT configuration, no port forwarding. Sounds too good to be true?
:eek:

Afraid to get your timbers wet ? Have you tried it ?

Note: doesn't work for me.

[Sooner Al]

Here is additional information...

http://www.microsoft.com/technet/itsolutions/network/p2p/default.mspx

Also this upgrade PNRP to PNRP version 2.0 for computers that are running Microsoft Windows XP SP2...

http://support.microsoft.com/kb/920342

[cszeto]

Keep in mind that as it overcomes IPv4 NAT, it also opens back up the file sharing issues that the NAT protected against. Set the files share configurations and/or firewall (XP SP2) settings accordingly.

[Greenstead]

I know about the PNRP version 2.0 for XP. I have it on my XP PCs.

Now I have two Vista PCs running I tried it Vista to Vista. Works OK with both PCs on the same LAN - can remote using the pnrp name. Does not work with one PC over the internet (name not found). I suspect my Vista pnrp names are not being published to the internet cloud.

[Sooner Al]

I see the same thing. In my case I also see a UDP Port open on my router, a NR041, for Teredo. The weird thing is only one port gets open and that is for the first PC/laptop, of my three running Vista, to get started/booted.

More than likely its an issue with your router like it is with mine not really supporting IPv6 yet. I do have an old BEFSR41 (v1) that I have not tested with Teredo and PNRP but hopefully will in the next few weeks. This is a quite old list but it includes a small test command you can use to see whats going on. I think you need to run it as an administrator to get accurate results, but I could be wrong about that...

http://www.microsoft.com/windowsxp/p2p/natcompat.mspx

Unfortunately I have not had a chance to test over the public internet yet with just the Windows Firewall between my PC/laptop and the internet...

[Greenstead]

I have used that test command to verify Teredo is going thru my routers.

>netsh interface ipv6 show teredo

A Vista PC at home gives:
Teredo parameters
------------------
Type : Default
Server name: teredo.ipv6.microsoft.com
Client refresh interval : 30 seconds
Client port : unspecified

An XP PC on the ADSL connection I use at the office I get:
Teredo parameters
------------------
Type : client
Server name: default
Client refresh interval : default
Client port : default
State : qualified
Type : teredo client
Network : unmanaged
NAT : restricted

Not sure what all this means but I cannot RDP to my Vista pnrp name.

[Sooner Al]

I got this working this morning...

http://www.dslreports.com/forum/remark,18126236