Elements of a Network Security Policy
In order to get a thorough understanding of what a network security policy is, it is instructional to analyze some of the most important elements of a security policy. RFC 2196 lists the following as the elements of a security policy: Computer Technology Purchasing Guidelines which specify required, or referred, security features. These should supplement existing purchasing policies and guidelines. A Privacy Policy which defines reasonable expectations of privacy regarding ..
The ability to recognize and define how to most efficiently summarize existing address ranges is an important skill on both the written and lab exams. For the written exam, the question may not be as straightforward as, “What is the most efficient summarization of the following subnets?” Rather, the math required for such a question might simply be part of a larger question. Certainly, such math is required for the lab exam. This section looks at the math behind finding t..
Types of Internetworking Devices
Cisco devices fall into three main categories: bridges and switches, routers, and access servers. We discuss bridges and switches first. Bridges and Switches A bridge is a network device that operates at the data link layer. A bridge connects multiple data link layer network segments into a single logical network segment. There are many different types of bridges: • Transparent or learning • Encapsulation • Translational • Source-route •&n..
Use the ntp authentication command to authenticate NTP traffic between associations. To configure an NTP enabled router to require authentication when other devices connect to it, use the following commands: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#ntp authentication-key 2 md5 oreilly Router1(config)#ntp authenticate Router1(config)#ntp trusted-key 2 Router1(config)#end Router1# Then you must configure th..
Allocating Static IP Addresses with DHCP
The following commands ensure that the router assigns the same IP address to a device each time it requests one: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#ip dhcp pool IAN Router1(dhcp-config)#host 172.25.1.33 255.255.255.0 Router1(dhcp-config)#client-identifier 0100.0103.85e9.87 Router1(dhcp-config)#client-name win2k Router1(dhcp-config)#default-router 172.25.1.1 Router1(dhcp-config)#domain-name or..
