Re: [pcp] To change a mapping does the pcp source port need remain the same?

Simon Perreault <simon.perreault@viagenie.ca> Mon, 17 September 2012 13:36 UTC

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Date: Mon, 17 Sep 2012 09:36:01 -0400
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Subject: Re: [pcp] To change a mapping does the pcp source port need remain the same?
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Le 2012-09-15 10:25, Eric W. Biederman a écrit :
> Would it be an error for a pcp server to require pcp clients to use
> the same source port that a mapping was established with to change
> that mapping?

Yes it would.

> As a trivial way to keep different clients from stepping on each other
> by accident I would certainly require the source port to remain constant
> to change a mapping.

Two issues I see:

- It would only be a convenience, not secure, because it would be 
trivial to guess and spoof.

- With long-lived mappings it becomes hard to guarantee that the same 
port will be used for all requests.

Simon
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