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Network Security
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Remote Authentication Dial-In User Service (RADIUS) RADIUS systems authenticate users on a client/server network Used for dial-in, wireless, and Internet access The server that hosts RADIUS is referred to as the Network Access Server (NAS) The NAS stores user names and passwords and records user activity on the network
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Rogue Wireless Access Points Rogue access point An unauthorized WAP that is installed on a network system. Rogue access point can compromise wireless network security Can be prevented by using a wireless intrusion prevention system (WIPS) or setting up an 802.1x system
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Authentication, Authorization, and Accounting (AAA) Standard that is most common model used for network access The dominate client/server security models that support AAA are RADIUS, TACACS+, and Diameter
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Diameter Applicable to roaming devices such as cell phones Allows for attributes to be added to basic Diameter protocol to meet AAA security requirements Any device acting as a relay between AAA authenticator and client is referred to as AAA proxyAAA proxy
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. TACACS+ Represents Terminal Access Controller Access- Control System plus Should not to be confused with TACACS; they are completely different systems Alternative to RADIUS
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. RADIUS and TACACS+ Comparison
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Password Authentication Protocol (PAP) Basic password authentication technique used for HTTP and remote dial-up access No longer used because user name and password are not encrypted
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Challenge Handshake Authentication Protocol (CHAP) CHAP was designed to be used with PPP Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) is an enhanced version of CHAP and can only be used on Microsoft operating systems Microsoft Challenge Handshake Authentication Protocol (MS-CHAP)
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. How CHAP Works 1.Client connects to a remote system using PPP 2.Server sends a challenge to the client 3.Server (authentication agent) sends a key to the client so it can encrypt its user name and password 4.Client responds with a key that represents its user name and password 5.Server accepts or rejects client user name and password based on a matching encryption key
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Kerberos Client and server authenticated to each other Encryption key (encodes data) and decryption key (decrypts data) used for privacy
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Extensible Authentication Protocol (EAP) Used for network access and authentication in a client/server environment when IP is not available Sends clear text messages Originally developed to be used with PPP Also used for 802.1x wireless connections and for access and authentication to network switches
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Protected Extensible Authentication Protocol (PEAP) Extension of EAP Works by first establishing a secure connection using Transport Layer Security (TLS) TLS provides encryption for the EAP connection and ensures data integrity
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Lightweight Extensible Authentication Protocol (LEAP) An improved EAP standard developed by Cisco Systems for its line of Wireless Access Points (WAPs) LEAP periodically re-authenticates the wireless connection This ensures client is still the original authenticated client and connection has not been hijacked
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Security Implementations Various measures include: Installing latest software updates and patches Setting up an account for daily administrative tasks Changing the default administrator’s name Educating system users in security practices
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Software Patches Should be applied: Immediately after installing new software As they become available Contain fixes that close security holes and fix software bugs Periodically, Microsoft releases a service pack for its software and operating systemsservice pack
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Administrator Account User provides password for default administrator account Default administrator account name should be changed to better secure network Ability to delete or rename the administrator account varies according to operating system
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. User Account Passwords To make passwords more secure administrators should: Set defaults for password histories, age, and length Educate users about poor and secure passwords
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Poor Passwords Poor passwords contain: Words that are found in a dictionary Names familiar to the password owner Keyboard patterns Social security numbers Secure passwords are less vulnerable to hashing techniqueshashing
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Windows Server 2008 Password Policies
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Firewall Can consist of hardware, software, or a combination Servers, routers, and PCs may be used Designed to filter inbound and outbound flow of network packets based on factors such as IP address Port number Software application Packet contents Protocol
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Firewall Example
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Windows Firewall with Advanced Security
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Packet Filter Stateless packet inspection Stateless packet inspection Does not take into account packet sequence or missing packets Aligns with layer 3 of the OSI model Stateful packet inspection Stateful packet inspection Applies a filter based on packet sequence Detects missing packets Aligns with layer 3 and 4 of the OSI model
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Application Gateway
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Content Filter Configured to block specific Web sites or packet contents that contain specific terms Administrator can control the list of terms Can also incorporate protection from malware
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Circuit-Level Gateway After connection is established, packet can flow freely between the two hosts Packet sequence is encoded, making it difficult for intruders to access stream of data
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Firewall Signature Identification Requires constant updates of new signatures No signature immediately available for new malware
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Demilitarized Zone (DMZ) Can be created with a router or a server with three network adapters installed When configured with a server One network adapter connects to the Internet A second network adapter connects to the DMZ The third network adapter connects to the private section of the network
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Proxy Server Can be configured to allow packets to flow into and out of the network if they meet certain conditions Specific IP addresses Certain protocols Server names or URLs May cache frequently visited Web sites, making it faster to access those Web sites
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Physical Security Physically securing file servers, hubs, routers, workstations, or any other point of access Locating network devices in secure rooms Biometrics—Identifying unique features such as fingerprints, speech, eye color, and facial features Biometrics Smart card—Access to computer systems is granted after correct PIN is entered Smart card
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Security Tools Identify network security weaknesses Probe network, searching for vulnerabilities Some security tools used are GFI LANguard Netstat utility Audit tools Self-hack tools Protocol analyzer Protocol analyzer Packet sniffer Packet sniffer
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. GFI LANguard
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Data Security Compliance Requirements Several security standards and laws have been created to secure user personal information Health Insurance Portability and Accountability Act (HIPAA) Health Insurance Portability and Accountability Act (HIPAA) Payment Card Industry Data Security Standard (PCI DSS) Payment Card Industry Data Security Standard (PCI DSS) California SB 1386 California SB 1386 Sarbanes-Oxley (SOX) Sarbanes-Oxley (SOX)
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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. In class lab 1. Apply for a trial version of a digital certificate from a CA such as Verisign. After obtaining the digital certificate try it out with a classmate. 2. Labsim 8.34 3. Roberts Lab 74 N EXT C LASS November 18 th, 2013 Labsim Homework 8.4.1-8.4.3
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