Adding Default Routes to BGP

The final method covered in this chapter for adding routes to a BGP table is to inject default routes into BGP. Default routes can be injected into BGP in one of three ways: ■ By injecting the default using the network command ■ By injecting the default using the redistribute command ■ By injecting a default route into BGP using the neighbor neighbor-id default-information [route-map route-map-name] BGP subcommand When injecting a default route into BGP using the ne..

Creating the Topology Table

After the router knows who its neighbors are, it is able to create a topological database and assign successors and feasible successors for each route. The topology table has a record not only of feasible successors and successors but also of all received routes. The other routes are referred to as possibilities. The topology table in EIGRP manages the selection of routes to be added to the routing table.   The topology table includes the following information:&nb..

Improving FIBs: Fast IP Route-Lookup

With the staggering growth of the Internet and consequent demands on core Internet routers, the field of fast IP route-lookup has been the subject of intense interest. Although route churn in the Internet is relatively high, packet forwarding, rather than route-computation, is proving to be the critical area requiring optimization. This signifies that lookup time is optimized at the expense of routing table update time.  Route-lookup is the process of finding the best ..

The Core as the L2 Domain

One way to deploy IS-IS onto a three-layer hierarchy is to configure the network core as a single L2 routing domain and place the distribution and access layers into various L1 domains, as needed. This design closely mimics an OSPF network with area 0 in the core and the distribution and access layers contained within areas connected to area 0, as Figure 5-3 illustrates. Figure 5-3. Pure D2 Core in Three-Layer Hierarchy The advantages and disadvantages of constraining the..

Challenges Unique to WLAN Management

WLANs present several unique management challenges. Many relate to the physical aspects of the wireless environment, whereas some are the result of the dynamic nature of the wireless network and its mobile users and devices. Knowledge of these challenges will help ensure that you do not overlook these areas in framing your management strategy for the enterprise-class WLAN. Some of the most commonly experienced problems and challenges you will face include the following: •&..