Re: [BEHAVE] I-D Action:draft-ietf-behave-v6v4-xlate-06.txt

["Dan Wing" <[e-mail]>]

(off-list.)

See below. 

> -----Original Message-----
> From: [e-mail] 
> [mailto:[e-mail]] On Behalf Of Xing Li
> Sent: Monday, January 25, 2010 2:25 AM
> To: [e-mail]
> Cc: Behave Chairs
> Subject: Re: [BEHAVE] I-D Action:draft-ietf-behave-v6v4-xlate-06.txt
> 
> Hi, All,
> 
> For draft-ietf-behave-v6v4-xlate-05 during WGLC, we have 4 
> reviews, many
> active discussions on the mailing list and mails to the 
> authors. Thanks
> for the reviews and comments. Here is a summary of the main issues
> discussed during WGLC.
> 
> (1) Discussion if translator is a router (for TTL/Hop-limit handling)
> Conclusion: Translator is a router. We made the wording consistent in
> different places of the document (in sections 1.4, 2.1, 2.7, 3.1 and
> 3.6. of the xlate-05)
> 
> (2) Discussion if the translator handles TTL/Hop limit before or after
> the translation.
> Conclusion: Leave it for the implementation.
> 
> (3) Handling of nested ICMP error messages.
> Conclusion: This process SHOULD stop at first embedded header and drop
> the packet if it contains more.
> 
> (4) Translating pointer in Parameter Problem
> Conclusion: Move Appendix 1 to sections 2.3 and 3.2 of the xlate-05.
> Remove ambiguous by setting the pointer value to the first 
> octet of the
> specific field if that field contains multiple octets.
> 
> (5) What MUST/SHOULD a translator do if the derivation fails for a
> source address?
> Conclusion: Translator drops the packet which contains illegal source
> address.

The new text is this, and is in the "Translating from IPv4 to IPv6" section:

      If the translator gets an illegal source address (e.g. 0.0.0.0,
      127.0.0.1, etc.), the translator SHOULD silently drop the packet.

I suggest adding "(as discussed in Section 5.3.7 of [RFC1812])" to the end of
that sentence.


Can similar text be added to the "Translating from IPv6 to IPv4" section of
behave-v6v4-xlate?  Currently regarding stateless translation it says only:

   Source Address:  In the stateless mode, which is to say that if the
      IPv6 source address is within the range of a configured IPv6
      translation prefix, the IPv4 source address is derived from the
      IPv6 source address per [I-D.ietf-behave-address-format] section
      2.1.  Note that the original IPv6 source address is an IPv4-
      translatable address.

We probably want to also list IPv6 'martian addresses' (::1, for sure; perhaps
others?) should be simply dropped (no ICMP response), as was added for IPv4.


A question:  for debugging/troubleshooting, it seems useful to send an ICMP
when the source IPv6 address is outside the range of configured IPv6
translation prefix(es).  That is, add a sentence like this to the quoted
paragraph above:

  If the IPv6 source address is not within the range of configured IPv6
prefix(es), 
  the translator SHOULD respond with an ICMPv6 Type=1, Code=5 (Destination 
  Unreachable, Source address failed ingress/egress policy).

Thoughts on that idea?


> (6) How to deal with ICMP packets coming from IPv6 addresses 
> that aren't
> IPv4-translatable?
> Conclusion: In this case, the translator can ether do stateful
> translation or map them to an IPv4 address block as a holder 
> for all non
> IPv4-translatable IPv6 addresses.
> 
> (7) Other technical and editorial comments
> We have updated the document based on the suggestions.
> 
> We also combined sections 2.2 and 2.6 of the xlate-05, since IPv4 UDP
> with checksum zero is a special case of Transport-layer 
> Header Translation.
> 
> A general question: Should we add the terminology section in each
> document (for example in xlate)? Or list all terminologies in 
> the framework document (as the current framework does)?

On that, I don't have a preference.

-d


> Do we have rough consensus for the above issues? Are there any other
> issues?
> 
> Regards,
> 
> X. Li, C. Bao, F. Baker
> 
> 
> 
> [e-mail] 写道:
> > A New Internet-Draft is available from the on-line 
> Internet-Drafts directories.
> > This draft is a work item of the Behavior Engineering for 
> Hindrance Avoidance Working Group of the IETF.
> >
> >
> > 	Title           : IP/ICMP Translation Algorithm
> > 	Author(s)       : X. Li, et al.
> > 	Filename        : draft-ietf-behave-v6v4-xlate-06.txt
> > 	Pages           : 28
> > 	Date            : 2010-01-25
> >
> > This document specifies an update to the Stateless IP/ICMP
> > Translation Algorithm (SIIT) described in RFC 2765.  The algorithm
> > translates between IPv4 and IPv6 packet headers (including ICMP
> > headers) for both stateless and stateful modes.
> >
> > A URL for this Internet-Draft is:
> > 
> http://www.ietf.org/internet-drafts/draft-ietf-behave-v6v4-xla
> te-06.txt
> >
> > Internet-Drafts are also available by anonymous FTP at:
> > ftp://ftp.ietf.org/internet-drafts/
> >
> > Below is the data which will enable a MIME compliant mail reader
> > implementation to automatically retrieve the ASCII version of the
> > Internet-Draft.
> >   
> > 
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