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Re: Part Three: Field Variance Analysis
In message <9508112244.AA20004@ixextra2.watson.ibm.com>, Pau-Chen Cheng writes:
>Craig, I just glanced over your 3 parts. I have not thought them over in
>details
>yet. But I have a simple question :
>
> I got the impression if a IP header field is labeled "invariant" by you,
> it does not mean it will not be changed. It means that if it is changed,
> then the packet should be considered "bad". Is my impression correct ?
Yes. "Invariant = If this field changes, the packet is not authentic".
This is to say that there exists a set of fields, which I call invariant, that
MUST be passed through the network without change in order for the packet to
maintain authenticity. If these invariant fields are changed, then the packet
is not authentic. Which fields fall within this definition of invariant is
a decision that we need to make by some sort of reasonable consensus. I
described my conclusions as a starting point for this.
-Craig