Distributing Traffic in Ether Channel
Traffic in an EtherChannel is statistically load-balanced across the individual links bundled together. However, the load is not necessarily balanced equally across all of the links. Instead, frames are forwarded on a specific link as a function of the addresses present in the frame. Some combination of source and destination addresses (either MAC or IP addresses) is used to form a binary pattern used to select a link number in the bundle. Switches perform an exclusive-OR (XOR) operation on one...
Accessing the Route Processor
To begin interVLAN routing configuration, the route processor must first be accessed. On an external router, a terminal emulator program can be used to connect directly with the console port. If some IP connectivity is already available on the router, a telnet session can be opened to the router. An integrated or internal route processor must first be located in the switch chassis. Use the show module command on a Catalyst switch to get a listing of the installed modules (see Example 7-1). The...
Root Bridge Placement
While STP is wonderfully automatic with its default values and election processes, the resulting tree structure may perform quite differently than expected. The Root Bridge election is based on the idea that one switch is chosen as a common reference point, and all other switches choose ports that are closest to the Root. The Root Bridge election is also based on the idea that the Root Bridge can become a central hub that interconnects other legs of the network. Therefore, the Root Bridge can...
Answers to Chapter 6 QA Section
1 What is the basic unit of ATM data What is its basic format (header, payload, etc.) The basic ATM data unit is the cell. An ATM cell consists of a 5-byte header and a 48-byte payload. 2 What process allows an IP packet to be transported within ATM cells Segmentation and Reassembly (SAR) provided by the ATM Adaptation Layer (AAL). 3 What is an ATM edge device What Cisco devices can be used An ATM edge device interfaces native ATM to another media. For example, Cisco Catalyst switches (5000 and...
Full Duplex Fast Ethernet
As with traditional Ethernet, the natural progression to improve performance is to use full-duplex operation. Fast Ethernet can provide 100 Mbps in each direction on a switched connection, for 200 Mbps total throughput. This throughput is only possible when a workstation or server is directly connected to a switch port, or when two switches directly connect to each other. The Fast Ethernet specification also offers backward compatibility to support traditional 10 Mbps Ethernet. To provide this...
Answers to Chapter 5 QA Section
1 What is EtherChannel What types of switch links can it be used with EtherChannel is a method for aggregating multiple physical Ethernet ports into a single logical link. EtherChannel can be used with full-duplex Fast Ethernet or Gigabit Ethernet links. 2 How does an EtherChannel distribute broadcasts and multicasts Broadcasts and multicasts are sent across only one port of the bundle and are not distributed across the EtherChannel. 3 How is traffic distributed over an EtherChannel Traffic is...
Establishing VLAN Connectivity
Next, the route processor will need to have its interfaces configured to support connectivity to the necessary VLANs. This is accomplished using interfaces and commands that are unique to the route processor hardware. The following sections present this information for each type of link between the route processor and switches. Establishing VLAN Connectivity with Physical Interfaces External routers are connected to switches using traditional LAN media links. For example, Ethernet, Fast...
MLS Management Interface
When a RSM or router is configured to participate in MLS, the device uses the MLSP to send Hello messages, advertise routing changes, and announce the VLANs or MAC addresses of those interfaces on the devices participating in MLS. One interface on the MLS-RP must be identified as the management interface through which MLSP packets are sent and received. The MLSP management interface can be any MLS interface connected to the switch. Only one management interface needs to be specified. If no...
About the Authors
Tim Boyles is the Director of Network Architecture for Link Networks, a national CLEC which specializes in broadband data and communications solutions for small- and medium-sized businesses. Prior to that he worked as a Senior Consultant at Lucent Networkcare, formerly known as INS, where he was responsible for the design and implementation of large switch-based networks as well as multiple service provider projects. Tim has been in the networking business for 16 years with multiple vendor...
Exams Required for Certification
To certify for CCNP or CCDP, successful completion of a group of exams is required. The exams generally match the same topics that are covered in one of the official Cisco courses. Table 1-1 outlines the exams and the courses with which they are most closely matched. Course Most Closely Matching Exam Requirements Interconnecting Cisco Network Devices (ICND) Building Scalable Cisco Networks (BSCN) Building Cisco Multilayer Switched Networks (BCMSN) Building Cisco Remote Access Networks (BCRAN)...
Recommended Training Path for CCNP and CCDP
The recommended training path for the Cisco CCNP 2.0 and CCDP 2.0 professional level certifications is as follows Building Scalable Cisco Networks (BSCN) Covers the advanced routing protocols and the scaling issues involved with a large routed network with multiple protocols. Building Cisco Multilayer Switched Networks (BCMSN) Covers the switch infrastructure and the configuration in a large network environment. Building Cisco Remote Access Networks (BCRAN) Covers the dialup and RAS issues...
Cisco CCNP Switching Exam Certification Guide
Tim Boyles and Dave Hucaby, CCIE 4594 Cisco CCNP Switching Exam Certification Guide Copyright 2001 Cisco Systems, Inc. Cisco Press logo is a trademark of Cisco Systems, Inc. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the publisher, except for the inclusion of brief quotations in a review....
