Tutorial6_10 - router. The default = discard policy is in...

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Tutorial 6 – ICT211 Question 1 (a) Briefly describe the function of the packet filtering router (b) Describe 3 possible limitation of a Packet Filtering Router as a firewall. (c) Do you think that the packet filtering router can protect a network from receiving email with an attachment that contains a new virus? Explain. (d) Consider the following two filtering rules of a packet-filtering router. What do you think the rules try to achieve? Action Our Host Port External Host Port Allow XYZ 25 * * Block * * ABC * Action Our Host Port External Host Port Allow * * * * (e) Consider the following filtering rule regulating inbound traffic of a packet-filtering
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Unformatted text preview: router. The default = discard policy is in force. What do they try to achieve? Action Our Host Port External Host Port Block * * XYZ * Allow ABC 120 * * Question 2 (a) For the trusted systems, multilevel security is required. In this case, a subject at a high level may not convey information to a subject at a lower level. The multilevel secure system must enforce the concepts of No-read-up and No-writedown. Explain the concepts of No-read-up and No-write-down (b) Explain how the No-write-down rule is useful in the defense against the Trojan horse attack. (Please read the textbook, pages 334-336)....
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This note was uploaded on 09/06/2010 for the course IT ICt211 taught by Professor Tan during the Spring '10 term at Singapore Institute of Management.

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