Part III: Supporting Ethernet, Switches, and VLANs
Chapter 5. Shooting Trouble with Ethernet
A solid understanding of Ethernet is as essential as supporting TCP/IP today. Many people have been using Ethernet since they started networking. Others have used it since the "frozen yellow garden hose" days of 10BASE5. You have used it in all the scenarios and Trouble Tickets thus far and will continue to use it throughout the book and in the real world. Understanding and
supporting Ethernet not only applies to the CCNP certification but to all industry certifications.
This chapter assumes your understanding of the information from the previous chapters, including protocols, models, troubleshooting methods, support tools, and resources.
In this chapter you combine some of the tasks from the preceding two chapters to build this chapter's scenario. Following the scenario is a review of Ethernet concepts, symptoms, problems, and action plans. To help you gain practical experience, this chapter contains several walk- through scenarios and practical Trouble Tickets for you explore. For those of you who do not have equipment handy, there are many relevant figures, examples, and explanations so that you, too, can shoot trouble with Ethernet.
This chapter covers the following topics:
Scenario: Shooting Trouble with Ethernet A Brief Summary of Ethernet
Ethernet Frames Ethernet Addressing
Ethernet at the Physical Layer Shooting Trouble with Ethernet Trouble Tickets
Trouble Tickets Solutions
Supporting Website Files
You can find files and links to utilities that support this book on the Cisco Press website at www.ciscopress.com/1587200570. Even if you do not have a lab, you can take advantage of the supporting configuration files including the logs to understand device input and output. The files are listed throughout the chapters in italics.
In order to be able to read and work with some of the supporting files offered at www.ciscopress.com/1587200570, you may want to download some of the programs listed in Table I-1 in the Introduction.
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including
Scenario: Shooting Trouble with Ethernet
This chapter starts with the IPX hands-on scenario you left off with at the end of the Trouble Tickets in Chapter 4, "Shooting Trouble with Novell IPX." The goals of the Shooting Trouble with Ethernet scenario are for you to modify your routers according to Figure 5-1 and verify end-to-end connectivity. Hostb requires use of an IPX application on the gwise server, but it should also be able to communicate via IP to the other hosts. The rest of the scenario suggests IP as the routed protocol and Enhanced Interior Gateway Routing Protocol (EIGRP) as the routing protocol using autonomous system (AS) 500. The IP subnets are the circled numbers on the wires. There should be end-to-end IP connectivity between hosta and hostc.
Run IPX RIP on network number 516. The rest of the chapter deploys this scenario, so be sure to save your configurations before, during, and after you configure your devices.
Figure 5-1. Shooting Trouble with Ethernet
NOTE
My lab uses the 2514, 2501, 3640, 3620, and 2516 Cisco routers, but yours can include any number of devices that have similar interfaces. Connect the hosts off of r1e0 by way of a hub.
See Appendix C, "Equipment Reference," for the hardware used throughout this book.
Document your steps and any problems along the way. Save your work and don't forget to test things out.
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including
Remember, however, that there is not always one right or wrong way to accomplish the task or tasks presented. The ability to obtain the end result using good practices is extremely important in any real- world network. My ending configurations are printed starting in Example 5-1 through Example 5-5 so that you can compare your work. Use the previous troubleshooting checklists, your step-by-step
troubleshooting methodology, and the Ethernet checklist in Table 5-1 to assist in testing. Refresh your memory by looking back at Table 3-1 (IP Checklist) and Table 4-1 (IPX Checklist) now.
NOTE
A very quick way to eliminate all IPX commands on r2 through r5 is by using the global command no ipx routing.
Table 5-1. Ethernet Layer 1 and 2 Quick Troubleshooting Checklist
Isolating Problems Commands and Symptoms
Cable, NIC, hub, switch Physical inspection Protocol analyzer TDR/OTDR
NIC software configuration Segmentation
Concentrate on interfaces and controllers for lower-level targets
See IP and IPX Checklists for ping, trace, and other relevant router/desktop tools.
show ip interface brief show ipx interface brief show controllers
show interfaces [interface]
show ip interface [interface]
show ipx interface [interface]
Drivers www.winfiles.com
www.driverguide.com Encapsulation
Know your frame types
show interfaces [interface]
show ipx interface brief NIC diagnostics/properties Autonegotiation
Speed issues cause connectivity problems Duplex issues cause performance problems
show interface [interface]
Collisions on a full-duplex link, for example.
One-way link
You can receive but can't transmit or vice versa
Check the cable.
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including
Example 5-1. r1 Configuration (2514)
r1#show running-config Building configuration...
Current configuration:
version 12.0
service timestamps debug uptime service timestamps log uptime no service password-encryption hostname r1
enable secret 5 $1$m0s2$Pq/6.NpOCSzhbQlNy.cnG/
enable password donna ip subnet-zero
ipx routing 1111.1111.1111 ipx ping-default novell interface Ethernet0
description r1e0 to hosta and hostb ip address 192.168.5.17 255.255.255.240 no ip directed-broadcast
ipx encapsulation SAP ipx network 516
interface Ethernet1
description r1e1 to r2e0
ip address 192.168.5.33 255.255.255.240 no ip directed-broadcast
interface Serial0
description r1s0 to r5s0 bandwidth 64
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including ip address 10.1.1.1 255.255.255.0
no ip directed-broadcast no ip mroute-cache
no fair-queue interface Serial1
description r1s1 to r3s0/0 bandwidth 64
ip address 192.168.5.81 255.255.255.240 no ip directed-broadcast
router eigrp 500 network 10.0.0.0 network 192.168.5.0 no auto-summary ip classless
tftp-server flash:c2500-js-l.120-21a.bin line con 0
logging synchronous transport input none line aux 0
line vty 0 4 password donna login
end
Example 5-2. r2 Configuration (2501)
r2#show running-config
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including Building configuration...
Current configuration:
version 12.0
service timestamps debug uptime service timestamps log uptime no service password-encryption hostname r2
enable secret 5 $1$5FjB$OHtAhTOCisLWIa5qzy3RJ1 enable password donna
ip subnet-zero interface Ethernet0
description r2e0 to r1e1
ip address 192.168.5.34 255.255.255.240 no ip directed-broadcast
interface Serial0
description r2s0 to r3s0/1 bandwidth 64
ip address 192.168.5.65 255.255.255.240 no ip directed-broadcast
no ip mroute-cache no fair-queue interface Serial1
description r2s1 to r3s0/2 bandwidth 64
ip address 192.168.5.49 255.255.255.240 no ip directed-broadcast
router eigrp 500 network 192.168.5.0
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including ip classless
line con 0
logging synchronous transport input none line aux 0
line vty 0 4 password donna login
end
Example 5-3. r3 Configuration (3640)
r3#show running-config Building configuration...
Current configuration:
version 12.0
service timestamps debug uptime service timestamps log uptime no service password-encryption hostname r3
enable secret 5 $1$VA..$TqTkW/PwrI4bRPF1zjZCu1 enable password donna
ip subnet-zero interface Serial0/0
description r3s0/0 to r1s1 bandwidth 64
ip address 192.168.5.82 255.255.255.240
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including no ip directed-broadcast
no ip mroute-cache no fair-queue clockrate 64000 interface Serial0/1
description r3s0/1 to r2s0 bandwidth 64
ip address 192.168.5.66 255.255.255.240 no ip directed-broadcast
clockrate 64000 interface Serial0/2
description r3s0/2 to r2s1 bandwidth 64
ip address 192.168.5.50 255.255.255.240 no ip directed-broadcast
clockrate 64000 interface Serial0/3
description r3s0/3 to r4s0/0 bandwidth 64
ip address 10.2.2.1 255.255.255.0 no ip directed-broadcast
...
interface FastEthernet2/0 description r3fa2/0 to hostc
ip address 192.168.5.97 255.255.255.240 no ip directed-broadcast
router eigrp 500 network 10.0.0.0
• Table of Contents
• Index
CCNP Practical Studies: Troubleshooting By Donna L. Harrington
Publisher: Cisco Press Pub Date: April 04, 2003
ISBN: 1-58720-057-0 Pages: 840
Hands-on practice for the CCNP Troubleshooting exam with TCP/IP, LAN, and WAN trouble tickets based on Cisco Internetwork Troubleshooting (CIT) topics.
With this book, you can:
Set up and follow along with real-world lab scenarios aligned to each exam topic, with or without the actual equipment
Establish a baseline and document your physical and logical network
Identify troubleshooting targets using ping, trace, show, clear, debug, and other troubleshooting tools and utilities
Diagnose and troubleshoot actual problems by following along with author-provided Catalyst(r) OS and Cisco IOS(r) Software command input, output, and logging Use instructor-developed problem-isolation methods to resolve Trouble Tickets
"Sniff" the wire to spot network issues
Analyze local and remote access problems in Ethernet networks, including issues with cabling, speed and duplex, utilization and collisions, bandwidth, CSMA/CD, one-way link, auto negotiation, addressing, encapsulation, and more
Apply a layered troubleshooting methodology to real-life routing and switching environments
Designed for aspiring CCNP and CCIE(r) professionals, this indispensable lab guide builds on Cisco(r) Internetwork Troubleshooting (CIT) topics that prepare you for the CCNP
Troubleshooting exam. Full of practical exercises that get you ready for challenges on the job, CCNP Practical Studies: Troubleshooting gives you an edge over the competition through real- world application of LAN and WAN topics.
CCNP Practical Studies: Troubleshooting provides you with practical information on all the important concepts central to the troubleshooting portion of the CCNP certification, including network 192.168.5.0
no auto-summary ip classless line con 0
logging synchronous transport input none line aux 0
line vty 0 4 password donna login
end
Example 5-4. r4 Configuration (3620)
r4#show running-config Building configuration...
Current configuration:
version 11.3
service timestamps debug uptime service timestamps log uptime no service password-encryption hostname r4
enable secret 5 $1$C0Dd$kkBg8CqXD2ZVjcHq8uvxB/
enable password donna interface Ethernet0/0 no ip address
shutdown