Class A network numbers are limited resources, and the allocation from this space is restricted. Although Class A space will continue to be distributed, it's now being allocated on a subnetwork basis, rather than in entire classful boundaries. Class B addresses are restricted as well, and are allocated on a subnetwork basis. Class C addresses are usually allocated from the upstream service provider's address space. Table 3-4 summarizes the current allocation of Class C addres..
Security is one of the most important features of a wireless LAN. Companies and home users must protect their information from hackers. The 802.11 standard offers security mechanisms that have undergone significant scrutiny over the past few years. Recently, improvements have been made by the Wi-Fi Alliance and via newer versions of the 802.11 standard. The most common wireless security mechanisms currently in use today are as follows: ■ Wired Equivalent Privacy (WEP) ■..
User Mode and Privileged Mode AAA Authentication
The term authentication, authorization, and accounting (AAA) refers to a variety of common security features. This section focuses on the first “A” in AAA—authentication—and how it is used to manage access to a router or IOS switch’s user mode and privileged mode. The strongest authentication method to protect the CLI is to use a TACACS+ or RADIUS server. The Cisco Secure Access Control Server (ACS) is a Cisco Systems software product that can be installed on Unix,..
Network Fault Tolerance and MPLS OAM Mechanisms
Operation, administration, maintenance, and provisioning (OAM&P) encompass a broad set of management functional areas, including fault management, configuration management, accounting management, and security management.[20] A fault (or defect) is an interruption of the capability of a network connection caused by a network element such as link and node failures. Discussion of functions in this section is restricted to fault management and performance management: • ..
When an OSPF network grows beyond a single area, you need to be aware of the role played by each OSPF router in a topology. Specifically, four OSPF router types exist: ■ Internal router: All the networks directly connected to an internal router belong to the same OSPF area. Therefore, an internal router has a single link-state database. ■ Area border router (ABR): An ABR connects to more than one OSPF area and therefore maintains multiple link-state databases (one for e..
