Subject: (ngtrans) RE: Query about automatic tunneling and ND

From: "Tony Hain" <[email-masked]>
Date: Tue, 8 Oct 2002 21:55:10 -0700

Anurag Uxa wrote:
> Dear Mr. Tony and all
> 
> I have two queries . Can you pls give me the details. and 
> tell me about some usefull document .
> 
> Questions:
> 1.
> HOST1 and HOST2 are in different networks and having IPv6 
> addresses HOST1 send one tunneled IPV4 packet <Encapsulated 
> IPV6 UDP packet> to the HOST2
>             (Before sending the tunneled packet out, Will the 
> HOST1 send tunneled mulitcast NS to HOST2 ?<For Reachability 
> Confirmation>)

No, there is no need for NS because the necessary 'link' reachability
information is already imbedded in the IPv6 address.

> 
> 2.
> Is Automatic tunnels always unidirectional or only for 
> following condition [Neighbor Discovery and Stateless Address 
> Autoconfiguration] ?

Yes they are always unidirectional. 

> 
> P.S: RFC-2893
> Automatic tunnels and unidirectional configured tunnels are 
> considered to be unidirectional. Thus the only aspects of Neighbor
> 
> Discovery [7] and Stateless Address Autoconfiguration [5] 
> that apply to these tunnels is the formation of the 
> link-local address.

Don't spend too much time on 2893 type automatic tunnels. The
replacement
http://www.ietf.org/internet-drafts/draft-ietf-ngtrans-mech-v2-00.txt
has removed them for lack of ability to scale well. 
Spend more time on RFC 3056, 
http://www.ietf.org/internet-drafts/draft-ietf-ngtrans-isatap-04.txt, 
& http://www.ietf.org/internet-drafts/draft-ietf-ngtrans-shipworm-08.txt

Tony

> 
> 
> 
> 
> 
> Thanks
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> IF U FIND SOME ONE WITHOUT A SMILE,GIVE ONE OF YOUR'S
> 
> Anurag Uxa
> IWave Embedded systems
> Bangalore
> ph.6786243/5 extn :210
> 
> 
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