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The mfn 3
- 1. The MFN backbone consists of a fiber-optic Gigabit Ethernet network that runs through the city in a ring topology. The fiber-optic ring connects the hybrid fiber- coax nodes that bring coax cabling to each neighborhood. Also connected to the ring are six data routers. Each router links one or more Mapleland businesses to MFN via simple point-to-point connections. At the business, the fiber-optic network enters the building and connects to a media converter. A UTP cable connects to the media converter and typically to a 100-Mbps Ethernet switch. The switch links the business’s computers and servers in a star topology via UTP cab 1.Draw a network map that shows the topology of the MFN and how the main components are connected. 2.What other information would you gather to improve your map and add more detail? 3.Mapleland is considering expanding the MFN to include wireless access for its residences. What additional investigation will you do to prepare for a citywide wireless network? 4.What security concerns do you have for the wireless network? Design Scenario 1. Draw a network map that shows the topology of the MFN and how the main components are connected.
- 2. 2. What other information would you gather to improve your map and add more detail?
- 3. a) Port details on the routers and the switches b) Cable lengths for the utp and fiber c) Fiber pairs on the backbone d) Number of clients on the network e) Ip address used in each subnets f) Bandwidth from isp to the clients distribution g) Type of routers and switches capability h) Servers back up and redundancy cables 3. Mapleland is considering expanding the MFN to include wireless access for its residences. What additional investigation will you do to prepare for a citywide wireless network? a) Where the users are located. b) Characteristics of the access points’ antennas, and the location of major obstructions. c) Checking Architectural and Environmental Constraints: d) Checking a Site for other Wireless Installation and The initial placement of an access point is based on an estimate of the signal loss that will occur between the access point and the users of the access point. e) Checking RF signal traveling through objects of various sorts can be affected by many different problems, including the following: I. Reflection: causes the signal to bounce back on itself. The signal can interfere with itself in the air and affect the receiver’s capability to discriminate between the signal and noise in the environment. II. Absorption: Some of the electromagnetic energy of the signal can be absorbed by the material in objects through which it passes, resulting in a
- 4. reduced signal level. Water has significant absorption properties, and objects such as trees or thick wooden structures can have a high water content. III. Refraction: When an RF signal passes from a medium with one density into a medium with another density, the signal can be bent. IV. Diffraction: results when a region through which the RF signal can pass easily is adjacent to a region in which reflective obstructions exist. 4. What security concerns do you have for the wireless network? a) Accidental association When a user turns on a computer and it latches on to a wireless access point from a neighboring company’s overlapping network, the user may not even know that this has occurred. However, it is a security breach in that proprietary company information is exposed and now there could exist a link from one company to the other. This is especially true if the laptop is also hooked to a wired network. B Malicious associations “Malicious associations” are when wireless devices can be actively made by attackers to connect to a company network through their cracking laptop instead of a company access point (AP). b) Ad hoc networks Ad hoc networks are defined as peer-to-peer networks between wireless computers that do not have an access point in between them. While these types of networks usually have little protection, encryption methods can be used to provide security. c) Non-traditional networks Non-traditional networks such as personal network Bluetooth devices are not safe from cracking and should be regarded as a security risk. Evenbarcode readers, handheld PDAs, and wireless printers and copiers should be secured. These non-traditional networks can be easily overlooked by IT personnel who have narrowly focused on laptops and access points. d) Identity theft (MAC spoofing)
- 5. Identity theft (or MAC spoofing) occurs when a cracker is able to listen in on network traffic and identify the MAC address of a computer with network privileges. . e) Man-in-the-middle attacks A man-in-the-middle attacker entices computers to log into a computer which is set up as a soft AP (Access Point). Once this is done, the hacker connects to a real access point through another wireless card offering a steady flow of traffic through the transparent hacking computer to the real network. The hacker can then sniff the traffic. One type of man-in-the-middle attack relies on security faults in challenge and handshake protocols to execute a “de-authentication attack”. 6 Denial of service A Denial-of-Service attack (DoS) occurs when an attacker continually bombards a targeted AP (Access Point) or network with bogus requests, premature successful connection messages, failure messages, and/or other commands. These cause legitimate users to not be able to get on the network and may even cause the network to crash. These attacks rely on the abuse of 7 Network injection In a network injection attack, a cracker can make use of access points that are exposed to non- filtered network traffic, specifically broadcasting network traffic such as “Spanning Tree” (802.1D), OSPF, RIP, and HSRP. The cracker injects bogus networking re-configuration commands that affect routers, switches, and intelligent hubs. A whole network can be brought down in this manner and require rebooting or even reprogramming of all intelligent networking devices. 8 Caffe Latte attack The Caffe Latte attack is another way to defeat WEP. It is not necessary for the attacker to be in the area of the network using this exploit. By using a process that targets the Windows wireless stack, it is possible to obtain the WEP key from a remote client.[8] By sending a flood of encrypted ARPrequests, the assailant takes advantage of the shared key authentication and the message modification flaws in 802.11 WEP. The attacker uses the ARP responses to obtain the WEP key in less than 6 minutes.[9]