Neighbor Discovery and Recovery

Using reliable updates produces two new problems: • The router needs to know how many other routers exist, so it knows how many acknowledgements to expect. • The router needs to know whether a missing advertisement should be interpreted as "no new information" or "neighbor disconnected." EIGRP uses the concept of neighborship to address these problems. EIGRP produces hellos periodically. The first hellos are used to build a list of neighbors; thereafter, hellos indicate ..

Topology Changes without Feasible Successor

Figure 8-4 shows a case in which there is no feasible successor.   Figure 8-4. Convergence without a Feasible Successor   If the link between router 2 and router 4 fails in Figure 8-4, router 4 will become active for destination N because it has no feasible successors.   Router 4 will send a query to router 3 and router 5. Both of these routers have no feasible successors, so they become active for destination N. Because router 3 and router..

Native IOS Mode Configuration

Figure 18-3 extends the discussion in the previous section to present a conceptual diagram of the Catalyst 6000 Native IOS Mode. Figure 18-3. Conceptual Diagram of the MSFC Native IOS Mode   In Figure 18-3, the Gigabit Ethernet ports on the Supervisor (1/1 and 1/2) have been configured as fully routed interfaces. Slot 5 contains a Fast Ethernet line card. Ports 5/1–5/3 have been configured as Layer 2 switchports in VLAN 2. Ports 5/4–5/6 have been configured as..

Technical Overview of Cisco IOS Frame Relay Compression Schemes

This section introduces the different compression schemes for Frame Relay that are supported by the Cisco IOS software. In general, users select a compression scheme that falls under either the payload compression scheme or packet header compression scheme.   Data Payload Compression Schemes   The Cisco IOS software supports a packet-by-packet payload compression scheme using Stacker compression. The Cisco packet-by-packet payload compression for Frame Relay feature..

Choosing the Best OSPF Routes

 All this effort to define LSA types, create areas, and fully flood the LSAs has one goal in mind: to allow all routers in that area to calculate the best, loop-free routes for all known subnets. Although the database exchange process may seem laborious, the process by which SPF calculates the best routes requires a little less thought, at least to the level re- quired for the CCNP ROUTE exam. In fact, the choice of the best route for a given subnet, and calculated by a ..