A multicast address identifies a group of interfaces; traffic sent to the group goes to all of the interfaces. Interfaces can belong to many multicast groups simultaneously. Each interface should recognize several multicast addresses, including the all-nodes multicast, the solicited-nodes multicast, and any other group addresses to which the node belongs. Routers should also recognize the all-routers multicast address. Figure 20-6 illustrates the format of an IP..
Route Map set Commands for Route Redistribution
When used for redistribution, route maps have an implied action—either to allow the route to be redistributed or to filter the route so that it is not redistributed. As described earlier in this chapter, that choice is implied by the permit or deny option on the route-map command. Route maps can also change information about the redistributed routes by using the set command. Table 11-3 lists the set command options when used for IGP route redistribution. Table 11-3 set Com..
Summarization hides details in order to simplify the routing process. One of the keys to scalable routing is to take large complicated sets of advertisements and reduce them as much as possible. Summarization reduces router resource consumption (CPU and memory) required to store and process routes by reducing the number of routes. Summarization also saves network capacity, because fewer advertisements are required and each advertisement is smaller. Summarization also hi..
Basic Single Area IS-IS Configuration
This section examines the process of configuring a single IS-IS area using the network in Figure 7-11. Figure 7-11. Single Area IS-IS Network [View full size image] The steps for a basic single area IS-IS configuration are as follows: Step 1. Configure a loopback interface on each OSPF router. Step 2. Configure IP addresses on the physical interfaces. Step 3. Configure the IS-IS process on each router. Step 4. Enable IS-IS on the router interfaces. The loopback addresses, ..
After an STP topology has converged and becomes loop free, switch ports are assigned the following roles: ■ Root port—The one port on a switch that is closest (with the lowest root path cost) to the root bridge. ■ Designated port—The port on a LAN segment that is closest to the root. This port relays, or transmits, BPDUs down the tree. ■ Blocking port—Ports that are neither root nor designated ports. ■ Alternate port—Ports that are candidate root ports (they a..
