If there is an issue building a multicast routing table, a good place to start troubleshooting is to verify that PIM sees its neighbors. Use the show ip pim interface command to look at settings on the interfaces, as shown in Example 19-2. This command shows the assigned (unicast) IP address; the interface name; the PIM version (1 or 2) and mode (dense, sparse, or sparse-dense); number of neighbors; frequency of queries; and the designed querier. Exam..
The point-to-point model is the most robust of the four models—each PVC is treated as a point- to-point subinterface. Therefore, losing a single PVC does not cause loss of connectivity. Instead, each point-to-point subinterface is a separate subnet. Each PVC can have different costs, according to the CIR. Point-to-point has faster convergence than any other model and allows for partial mesh. The point-to-point model has a serious problem with flooding, however..
PPP Layer 2 Payload Compression
Cisco IOS software supplies three different payload compression options for PPP, namely Lempel-Ziv Stacker (LZS), Microsoft Point-to-Point Compression (MPPC), and Predictor. Stacker and MPPC both use the same underlying Lempel-Ziv (LZ) compression algorithm, with Predictor using an algorithm called Predictor. LZ uses more CPU and less memory in comparison to Predictor, and it typically results in a better compression ratio. Table 17-7 summarizes some of the key points regar..
Standards Bodies and Incident Response Teams
Numerous standards bodies today help a network administrator design a sound security policy. The two main entities that are helpful are the Computer Emergency Response Team Coordination Center (CERT/CC) and the various newsgroups that enable you to share valuable security information with other network administrators. CERT/CC is a U.S. federally-funded research and development center at Carnegie Mellon University in Pittsburgh, Pennsylvania. Following the infamous worm incid..
An AP can provide WLAN connectivity to only the clients within its range. The signal range is roughly defined by the AP’s antenna pattern. In an open-air setting, this might be a circular shape surrounding an omnidirectional antenna. At least the pattern will appear as a circle on a floor plan—keep in mind that the pattern is three-dimensional, also affecting floors above and below, in a multilevel building. The AP’s location must be carefully planned so that its range..
