Unlike IGRP, EIGRP must establish neighbor relationships before updates are sent out. When an EIGRP process is configured on the router, the router begins to exchange EIGRP hello packets over the multicast address of 224.0.0.10. Neighbor relationships form between routers when they receive each other's hello packet. Over LAN broadcast media such as Ethernet, Token Ring, or FDDI, the hello packets are sent every 5 seconds. Over WAN multipoint interfaces with a bandwidth of T1 ..
Legacy Layer 3 Queuing Mechanisms
There is a long history of queuing algorithms in Cisco IOS Software, not all of which are covered in this chapter because they are not applicable to QoS deployment for converged networks. Newer queuing and scheduling algorithms are simply combinations and enhancements of older queuing algorithms. For a historical perspective and an understanding of why these mechanisms are insufficient for today's converged networks, it is helpful to review some of these legacy queuing techni..
Consider a network design that consists of Layer 2 devices only. For example, this design could be a single Ethernet segment, an Ethernet switch with many ports, or a network with several interconnected Ethernet switches. A full Layer 2–only switched network is referred to as a flat network topology. A flat network is a single broadcast domain, such that every connected device sees every broadcast packet that is transmitted. As the number of stations on the network increase..
Table 1-1 summarizes the common Frame Relay terminology you will continue to see throughout this book. Table 1-1. Common Frame Relay Terminology Term Definition Description CIR Committed Information Rate Rate in bps at which the network commits to transfer user data under normal conditions, averaged over a minimum time interval, Tc. EIR Excess Information Rate The maximum rate in bps in excess of the ..
You can manually configure trunk links on Catalyst switches for either ISL or 802.1Q mode. In addition, Cisco has implemented a proprietary, point-to-point protocol called Dynamic Trunking Protocol (DTP) that negotiates a common trunking mode between two switches. The negotiation covers the encapsulation (ISL or 802.1Q) and whether the link becomes a trunk at all. This allows trunk links to be used without a great deal of manual configuration or administration. The use ..
