Subject: Re: New Consensus call on RH0 Deprecation

From: Tim Enos <[email-masked]>
Date: Tue, 21 Aug 2007 10:26:28 -0500 (CDT)

I would like to see the WG adopt option 1) for the same reasons as listed in Joe's e-mail.

>
>On 20-Aug-2007, at 16:43, Bob Hinden wrote:
>
>> We would like to get your comments on the following two choices:
>>
>> 1) Deprecate RH0 as specified in <draft-ietf-ipv6-deprecate- 
>> rh0-01.txt>.
>
>I support this option since:
>
>1. I think it is the clearest solution to the problem (as in, easiest  
>to understand). I believe clarity is important here, since ambiguity  
>seems like a path to "let's block all routing headers, just to be on  
>the safe side".

Exactly. It protects against the potential attacks outlined in the draft while taking great pains to encourage the preservation of other RH types (and the applications that rely upon them (e.g. RH2 and MIPv6)).

>
>2. It facilitates identification of "dangerous" source-routing in a  
>way that is already available on several platforms (checking the RH  
>type) without requiring devices to distinguish between old and new  
>semantics (as would be needed in the case of a shared codepoint  
>between the original and new specification).
>
>3. Architecturally, choosing a new codepoint for functionality which  
>is different, even if it is similar, seems like the right thing.
>
>4. It is congruent with the approach several significant  
>implementations have taken (e.g. Linux, *BSD, Mac OS X).

And just as pointed out by James Woodyatt, the latest firmware for the AirPort Extreme 802.11n base station.

>
>5. Nobody has come forward with an indication that functionality  
>requiring RH0 in its current form is widely deployed or required. It  
>seems at least plausible that we might expect to have heard of such a  
>use case given the publicity surrounding the CanSecWest presentation,  
>regardless of whether you choose to classify that publicity as  
>"hysteria" or "journalism" :-).
>
>6. It seems likely that some IPv6 operators have taken the precaution  
>of dropping datagrams carrying RH0, and hence the zero type might be  
>considered effectively poisoned for use on the public Internet. Re- 
>use of type zero would hence only be of reliable use within  
>controlled networks; to be of general use, a benign source routing  
>option would need a new codepoint.
>
>
>Joe

Best Regards,

Tim Enos
Rom 8:28-39

>
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