ietf-mxcomp
[Top] [All Lists]

Re: Will SPF/Unified SPF/SenderID bring down the 'net?

2004-06-28 21:37:41

Some more comments.

1)Just a note as to why this discussion is important:
It is very relevant to the current agenda item:

- Due 2004-07-02: Decide if CSV is complimentary, parts to be incorporated, or dropped.
Does CSV's greater DDoS resistance matter a lot? Or not?

2)On 6/28/04 5:56 PM, Hallam-Baker, Phillip sent forth electrons to convey:

Caller-Id required a single packet in each direction for the vas[t]
majority of mail interactions.
Do you see why I feld that this statement was incorrect, at least?

Please read the earlier post to this thread at
http://www.imc.org/ietf-mxcomp/mail-archive/msg02198.html

<>I don't see you addressing the concerns Doug raised.

... Does it work in the face of malicious macro SPF records?

Only if we decide to support the macro interface. I was hoping that
we would reject it on the grounds that all the use cases that have been stated can be implemented anyway.
Well, we have a decision to make by 7/2, and currently, macros are in the spec and likely to stay, so our decision should be based on that.

If what you are trying to say is that there must be some limit to the
complexity of a query I think that is correct, clearly it is a bad
thing if records branch out indefinitely.

I'm confident that, without such limits, SPF is likely to be turned off due to attacks on users. I'm saying that we need to explore further whether with limits high enough to allow necessary functionality, it can survive such attacks.


I asked before if you were arguing that all mail servers should rely on local caching DNS servers that will cache all the word's active LMAP records.
Are you?

I'm not trying to deep 6 SPF. I'm trying to make it stronger and better by attacking its weaknesses virtually, while they are readily fixable. Note, I recently expressed my support Unified SPF (which incorporates a CSV-like check). BTW, I was surprised that the -01 SenderID drafts that came out didn't have any Unified SPF stuff in 'em. I interpreted something Meng said to mean that I should expect to see it in a draft soon, so I'm still expecting that.