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aefstoggaflm
Open Source Fan
Premium
join:2002-03-04
Bethlehem, PA
kudos:7

How to tell by looking at an IPv6 Address is native or tunneled

?

And if tunneled, what kind of IPv4 to IPv6 tunnel?

Thank you

paul248

join:2001-09-04

1 recommendation

Just look at the prefix. 2002: is 6to4, and 2001:0: is Teredo.

Tunnels to a specific ISP don't follow a definite pattern, but you might be able to notice them using traceroute/tracepath, or by looking for an embedded hexadecimal IPv4 address.


whfsdude
Premium
join:2003-04-05
Washington, DC

1 recommendation

reply to aefstoggaflm
You could also look at the v4 and v6 addresses and determine if they're being advertised by the same ASN.


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
reply to paul248
said by paul248:

Just look at the prefix. 2002: is 6to4, and 2001:0: is Teredo.

Is "Teredo" the same as "6in4"?

--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


F430

@suddenlink.net

1 recommendation

quote:
Is "Teredo" the same as "6in4"
No. Teredo began as a Microsoft protocol but now is is an open standard. It encapsulates IPv6 datagrams in IPv4 UDP datagrams so is not really 6in4. In 6in4, the IPv4header is followed by the IPv6 packet being carried. No transport encapsulation is used. Teredo is much more complex then 6in4. Teredo is "friendly" with most types of IPv4 NAT. 6in4 is not NAT friendly.

paul248

join:2001-09-04
reply to NormanS
said by NormanS:

Is "Teredo" the same as "6in4"?

No, 6in4 is the generic term for stuffing an IPv6 packet into an IPv4 packet using Protocol 41. The addresses can be anything that the endpoints agree upon, even beef:beef:beef:beef:beef:beef:beef:beef.


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC

1 recommendation

reply to F430
said by F430 :

quote:
Is "Teredo" the same as "6in4"
No. Teredo began as a Microsoft protocol but now is is an open standard. It encapsulates IPv6 datagrams in IPv4 UDP datagrams so is not really 6in4. In 6in4, the IPv4header is followed by the IPv6 packet being carried. No transport encapsulation is used. Teredo is much more complex then 6in4. Teredo is "friendly" with most types of IPv4 NAT. 6in4 is not NAT friendly.

I asked because somebody once declared my 2001:470: tunnel as being Teredo, when it is really a Hurricane Electric 6in4.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10

1 recommendation

That somebody probably failed to look beyond the first quad (16 bits).