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CNIT 221

Security

Module 2 1 ver.2

City College of San Francisco Spring 2006

Network Security 1

Module 2 – Security Planning and Policy

Learning Objectives

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2.1 Discussing Network Security and Cisco

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2.2 Endpoint Protection and Management

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2.3 Network Protection and Management

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2.4 Security Architecture

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2.5 Basic Router Security Router(config)#

Module 2 – Security Planning and Policy

2.1 Discussing Network Security and Cisco

Network Security as a Continuous Process

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Network security is a continuous process built around a security policy.

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Step 1: Secure Secure

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Step 2: Monitor

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Step 3: Test

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Step 4: Improve Improve Security Policy Monitor Test Router(config)#

Secure the Network

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Implement security solutions to stop or prevent unauthorized access or activities, and to protect information:

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Authentication

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Encryption

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Firewalls

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Vulnerability patching Router(config)#

Secure Improve Security Policy Monitor Test

Monitor Security

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Detects violations to the security policy

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Involves system auditing and real-time intrusion detection

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Validates the security implementation in Step 1 Improve Secure Security Policy Test Monitor Router(config)#

Test Security

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Validates effectiveness of the security policy through system auditing and vulnerability scanning Improve Secure Security Policy Test Monitor Router(config)#

Improve Security

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Use information from the monitor and test phases to make improvements to the security implementation.

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Adjust the security policy as security vulnerabilities and risks are identified.

Improve Secure Security Policy Test Monitor Router(config)#

What Is a Security Policy?

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“A security policy is a formal statement of the rules by which people who are given access to an organization’s technology and information assets must abide.”

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(RFC 2196, Site Security Handbook) Router(config)#

Why Create a Security Policy?

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To create a baseline of your current security posture

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To set the framework for security implementation

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To define allowed and not allowed behaviors

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To help determine necessary tools and procedures

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To communicate consensus and define roles

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To define how to handle security incidents Router(config)#

Security Policy Elements Data Assessment Vulnerabilities Host Addressing Denial of Service Application Definition POLICY Misuse Usage Guidelines Reconnaissance Topology/Trust Model

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On the left are the network design factors upon which security policy is based

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On the right are basic Internet threat vectors toward which

Module 2 – Security Planning and Policy

2.2 Endpoint Protection and Management

Types of Firewalls

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Server Based Microsoft ISA CheckPoint Zone Alarm Appliance PIX Security Appliance/ASA Netscreen SonicWall Personal Norton McAfee ZoneAlarms Integrated IOS Firewall

Module 2 – Security Planning and Policy

2.3 Network Protection and Management

Sample Firewall Topology Router(config)#

VPN Definition Router(config)#

Remote Access VPNs Router(config)#

Site-to-Site VPNs Router(config)#

Adaptive Security Device Manager (ASDM) Router(config)#

Security Device Manager (SDM) Router(config)#

Module 2 – Security Planning and Policy

2.4 Security Architecture

Secure Connectivity Router(config)#

Cisco Threat Defense System Router(config)#

Identity Based Networking Services (IBNS) Router(config)#

Plan, Design, Implement, Operate, Optimize (PDIOO) Router(config)#

Module 2 – Security Planning and Policy

2.5 Basic Router Security

SSH TCP Port 22 SSH Client Router(config)#

SSH Server and Client

SSH Server Configuration Router(config)# hostname host-name Router(config )# ip domain-name domain-name.com Router(config )# crypto key generate rsa Router(config )# line vty 0 4 Router(config-line)# transport input ssh Router(config)#

Controlling Access

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Console Port

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TTY

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VTY

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A console is a terminal connected to a router console port.

The terminal can be a dumb terminal or PC with terminal

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Passwords Passwords are the most critical tools in controlling access to a router. There are two password protection schemes in Cisco IOS: Type 7 uses the Cisco-defined encryption algorithm.

Type 5 uses an MD5 hash, which is much stronger. Cisco recommends that Type 5 encryption be used instead of Type 7 where possible. Type 7 encryption is used by the enable password, username, and line password commands.

Service password encryption should be used.

Use good password practices when creating passwords.

Configure both username and password combinations.

Router(config)#

Good Password Practices

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Avoid dictionary words, names, phone numbers, and dates.

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Include at least one lowercase letter, uppercase letter, digit, and special character.

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Make all passwords at least eight characters long. Avoid more than four digits or same-case letters in a row.

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Change passwords often. Router(config)#

Initial Configuration Dialog --- System Configuration Dialog -- Would you like to enter the initial configuration dialog? [yes/no] y Configuring global parameters: Enter host name [Router]: Boston The enable secret is a password used to protect access to privileged EXEC and configuration modes. This password, after entered, becomes encrypted in the configuration.

Enter enable secret: CantGessMe The enable password is used when you do not specify an enable secret password, with some older software versions, and some boot images.

Enter enable password: WontGessMe The virtual terminal password is used to protect access to the router over a network interface.

Enter virtual terminal password: CantGessMeVTY Router(config)# .

Configure the Enable Password Using enable secret router(config)# enable secret password

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Encrypts the password in the router configuration file

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Uses a strong encryption algorithm based on MD5 Boston(config)# enable secret Curium96 Boston# show running-config !

hostname Boston !

no logging console enable secret 5 $1$ptCj$vRErS/tehv53JjaqFMzBT/ !

Router(config)#

Configure the Console Port User-Level Password router(config)# line console line-number

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Enters console line configuration mode router(config-line )# login

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Enables password checking at login router(config-line)# Password password

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Sets the user-level password to password Boston(config)# line console 0 Boston(config-line)# login Boston(config-line)# password ConUser1 Router(config)# Creates the user-level password ConUser1

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The password is unencrypted

Configure a VTY User-Level Password router(config)# line vty start-line-number end-line-number

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Enters VTY line configuration mode

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Specifies the range of VTY lines to configure router(config-line)# login

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Enables password checking at login for VTY (Telnet) sessions router(config-line)# password password

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Sets the user-level password to password Boston(config)# line vty 0 4 Boston(config-line)# login Boston(config-line)# password CantGessMeVTY

Configure an Auxiliary User-Level Password router(config)# line aux line-number

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Enters auxiliary line configuration mode router(config-line)# login

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Enables password checking at login for Aux connections router(config-line)# password password

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Sets the user-level password to password Boston(config)# line aux 0 Boston(config-line)# login Boston(config-line)# password NeverGessMeAux

Encrypting Passwords Using

service password-encryption

router(config)# service password-encryption

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Encrypts all passwords in the router configuration file Boston(config)# service password-encryption Boston# show running-config !

line con 0 password 7 0956F57A109A !

line vty 0 4 password 7 034A18F366A0 !

line aux 0 password 7 7A4F5192306A

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Uses a weak encryption algorithm that can be easily cracked

Setting Timeouts for Router Lines router(config-line)# exec-timeout minutes [seconds]

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Default is 10 minutes Terminates an unattended console connection Provides an extra safety factor when an administrator walks away from an active console session Boston(config)# line console 0 Boston(config-line)#exec-timeout 3 30 Boston(config)# line aux 0 Boston(config-line)#exec-timeout 3 30 connection after 3 minutes and 30 seconds

Setting Multiple Privilege Levels router(config)# privilege mode {level level command | reset command}

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Level 1 is predefined for user-level access privileges

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Levels 2 –14 may be customized for user-level privileges Level 15 is predefined for enable mode (

enable

command) Boston(config)# privilege exec level 2 ping Boston(config)# enable secret level 2 Patriot Router(config)#

Login Banner

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Banners should be used on all network devices

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A banner should include A notice that the system is to be logged into or accessed only by authorized personnel, and information about who may authorize use. A notice that any unauthorized use of the system is unlawful, and may be subject to civil and criminal penalties, or both. A notice that any use of the system may be logged or monitored without further notice, and that the resulting logs may be used as evidence in court. Specific notices required by specific local laws.

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A login banner usually should not contain any specific information about the router, its name, its model, what software it is running, or its ownership .

Configuring Banner Messages router(config)# banner {exec | incoming | login | motd | slip-ppp} d message d

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Specify what is “proper use” of the system

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Specify that the system is being monitored Specify that privacy should not be expected when using this system Do not use the word “welcome” Have legal department review the content of the message Boston(config)# banner motd # WARNING: You are connected to $(hostname) on the Cisco Systems, Incorporated network. Unauthorized access and use of this network will be vigorously prosecuted. #

Router(config)#

Title: First Slide in a Presentation

Transcript Title: First Slide in a Presentation

CNIT 221

Security

Module 2 1 ver.2

Module 2 – Security Planning and Policy

2.1 Discussing Network Security and Cisco

2.2 Endpoint Protection and Management

2.3 Network Protection and Management

2.4 Security Architecture

2.5 Basic Router Security

Directory