Preventing Suboptimal Routes by Setting the Administrative Distance
One simple and elegant solution to the problem of suboptimal routes on redistributing routers isto flag the redistributed routes with a higher AD. A route’s AD is not advertised by the routingprotocol; however, a single router can be configured such that it assigns different AD values todifferent routes, which then impacts that one router’s choice of which routes end up in that router’srouting table. For example, back in Figure 11-4 and Example 11-3, R3 could have assig..
Infrastructure Mode Configuration
An infrastructure wireless LAN (sometimes referred to as infrastructure mode) is what most companies, public hotspots, and home users implement. An infrastructure wireless LAN, as depicted in Figure 22-1, offers a means to extend a wired network. In this configuration, one or more access points interface wireless mobile devices to the distribution system. Each access point forms a radio cell, also called a basic service set (BSS), which enables wireless users located within t..
Sources Sending Packets to the Rendezvous Point
PIM-SM uses a two-step process to initially deliver multicast packets from a particular source to the hosts wanting to receive packets. Later, the process is improved beyond these initial steps. The steps for the initial forwarding of multicasts with PIM-SM are as follows: 1. Sources send the packets to a router called the rendezvous point (RP). 2. The RP sends the multicast packets to all routers/hosts that have registered to receive packets for that group. This process uses..
Network security is a system. It's not a firewall, it's not intrusion detection, it's not virtual private networking, and it is not authentication, authorization, and accounting (AAA). Security isn't anything that Cisco Systems or any of its partners or competitors can sell you. Although these products and technologies play an important role, network security is more compre-hensive. It all starts, as has become almost cliché in the industry, with a security policy. From ther..
Multicast over Frame Relay or ATM WANs
When using PIM-SM on an nonbroadcast multiple access (NBMA) network, such as a Frame Relay or ATM WAN, you must configure the ip pim nbma-mode interface command: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#ip multicast-routing Router1(config)#interface Serial0/0 Router1(config-if)#encapsulation frame-relay Router1(config-if)#ip pim sparse-mode Router1(config-if)#ip pim nbma-mode Router1(config-if)#end ..
