Reference no: EM133730010

Part 1: IDS Placement. Please refer to the accompanying network diagram as you consider and respond to the following:

Question 1: Global Corporation, Inc. (GCI) is a fictional company providing business services to a variety of clients across many industries, including commercial and government entities. GCI recently finished construction of a new corporate headquarters, which includes the network infrastructure for primary company operations. You are a security analyst specializing in intrusion detection brought in by GCI to help determine the most appropriate kinds of IDS to use and most effective IDS placements to protect their network.

Question 2: GCI's network uses a conventional three-zone architecture: devices exposed to the Internet are part of an un-trusted outer zone; Internet-accessible services such as the company website and email are in a demilitarized zone; and major systems and servers supporting both Internet-facing and internal applications as well as internal computing resources such as the corporate LAN are in a trusted zone. Each of these zones is segmented from the others using hardware-based firewalls; the corporate databases are further protected behind their own dedicated firewall. GCI allows employees remote access to the corporate LAN using either VPN or dial-up connections.

Question 3: Identify the locations throughout the GCI network where you would recommend IDS to be deployed. Each of the components in the accompanying GCI-HQ Network diagram is lettered to simplify your references to the diagram. For network connections between devices and layers, you may assume for the purposes of this exercise that all components in a given zone share the same network segment. For each placement you recommend, please note the type of IDS to be deployed and any specific considerations that should be taken into account to ensure the effective monitoring of the location.

Question 4. Describe how host-based intrusion detection works, briefly contrasting it with network-based intrusion detection. Explain three types of threats against which HIDS is particularly effective.

Question 5. If an attacker knew a network-based IDS was running in a targeted environment, how might the attacker try to evade detection? Provide at least two examples of IDS evasion techniques that might be used by an attacker, and suggest a remedy or defense against the techniques you cite.

Question 6. Compare and contrast signature-based and anomaly-based intrusion detection systems. In your analysis, describe at least three ways in which the two types of IDS are similar, and at least three ways in which they differ.

Question 7. There are 2 different approaches in writing signatures in Network based IDS. Explain about the two primary approaches, and compare them in terms of their strengths and limitations.

Part 2: Short Answers. Please answer briefly and completely, and cite all sources of information.(8 questions at 8 points each)

Question 1. Describe factors you need to consider in making a decision on whether an IDS needs to be deployed in a home network or not. Please give a detailed explanation on each factor.

Question 2. When you are placing an NIDS sensor in a network with a firewall, there are 2 choices - placing it before a firewall (i.e., on internet-side) vs. after a firewall (i.e., on local network side). Provide pros and cons of each approach.

Question 3. Examine the following screen-shot of a short packet capture in Wireshark. Describe the sequence of packets exchanged between the two systems participating in the conversation. What sort of traffic has been captured? What is happening in the sequence shown on the screen? Please provide as much details as possible for each packet.