[altq 907] Filters / filter intersection

[Nicolas Christin <nicolas@cs.virginia.edu>]

	Hi all-

	I have yet another question, this time about filters. I read the
documentation on the subject (in TIPS.txt) and I'm still a bit confused.
What I want to do is set a filter specifying "all traffic going between IP
address A and IP address B should be class 'high'". The traffic in
question is TCP, and I want the ACKs (on the reverse path) to belong to
class 'high'. If I use something like

	filter fxp1 high A 0 B 0 0

data packets will indeed belong to class high, but since the TCP ACKs are
sent from B to A, they won't match the filter. I would instead need to do
something like

	filter fxp1 high A 0 0 0 0
	filter fxp1 high 0 0 B 0 0

	Unfortunately, the above doesn't work: the second filter will
override the first one. Any suggestions? (Besides modifying the code
of the parser, which I can do as a last resort, but would rather avoid if
possible.) Also, I'd rather avoid having to define two classes with
exactly the same properties...

	--Nick


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Nicolas Christin                        nicolas@cs.virginia.edu
Multimedia Networks Group               http://www.cs.virginia.edu/~nc2y
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