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Mohamed G. Gouda						CS 386 S
Spring 2008							quiz 9&10
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Below is a Firewall Decision Diagram (FDD) that has two fields x and y. The
domain of (integer) values of each field is the interval [0,9].

a. Assign a mark "ALL" to exactly one outgoing edge of each internal node
   in the FDD.

b. Generate the (three) firewall rules from the marked FDD.

c. Compute the matching and resolving predicates of the last rule in the
   generated firewall.   


		---				       ---
		|x|-----------[0,1][4,5][8,9]--------->|a|
		---				       ---
		 |
		 |
	    [2,3] [6,7]
		 |
		 |
		 V
		---					---
		|y|--------------[0,2][5,9]------------>|a|
		---					---
		 |
		 |
	       [3,4]
		 |
		 |
		 V
		---
		|d|
		---

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Solution:

a. The marking is as shown below.


		---				       ---
		|x|-----------[0,1][4,5][8,9]--------->|a|
		---				       ---
		 |
		 |
	    [2,3] [6,7] ALL
		 |
		 |
		 V                 ALL
		---					---
		|y|--------------[0,2][5,9]------------>|a|
		---					---
		 |
		 |
	       [3,4]
		 |
		 |
		 V
		---
		|d|
		---

b. 

r1 : x in [0,1][4,5][8,9] and y in [0,9] --> a
r2 : x in [0,9] and y in [3,4] --> d
r3 : x in [0,9] and y in [0,9] --> a

c.

mp3 : x in [0,9] and y in [0,9]
rp3 : x in [2,3][6,7] and y in [0,2][5,9]

(Solution 2)


a. The marking is as shown below.


               ---                                    ---
               |x|-----------[0,1][4,5][8,9]--------->|a|
               ---                 ALL                ---
                |
                |
           [2,3] [6,7]
                |
                |
                V                 ALL
               ---                                     ---
               |y|--------------[0,2][5,9]------------>|a|
               ---                                     ---
                |
                |
              [3,4]
                |
                |
                V
               ---
               |d|
               ---

b.

r1 : x in [2,3][6,7] and y in [3,4] --> d
r2 : x in [2,3][6,7] and y in [0,9] --> a
r3 : x in [0,9] and y in [0,9] --> a

c.

mp3 : x in [0,9] and y in [0,9]
rp3 : x in [0,1][4,5][8.9] and y in [0,9] --> a