This chapter addresses various CCNP Support WAN topics. It includes scenarios and Trouble Tickets for High-Level Data Link Control (HDLC), Point-to-Point Protocol (PPP), Integrated Services Digital Network Basic Rate Interface (ISDN BRI), and Dial Backup. It is assumed you have internetworking experience particularly with IP and routing protocols in the WAN. You will analyze these WAN technologies individually and together for more practical application. This chapter in combination with the previous chapters prepares you for the next chapter and practical internetwork support where you must integrate various skills and predefined troubleshooting methods to solve numerous issues.
In supporting the WAN, many times the battle is deciding whether the problem is in fact yours or whether it is a service provider issue. You will analyze real-world WAN issues, identify
troubleshooting targets, and document the results using ping, trace, show, clear, debug and other troubleshooting utilities. Gain practical experience by following the text, figures, and examples or use my guidelines to build the scenarios and Trouble Tickets yourself.
This chapter covers the following topics:
Scenario: Shooting Trouble on the WAN WAN Terminology
HDLC PPP ISDN BRI
Dial-on-Demand Routing Dial Backup
Trouble Tickets
Trouble Ticket 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
• 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 on the WAN
This chapter uses some of the same devices you have been working with throughout the book.
First you need to adjust your physical topology as shown in Figure 9-1. You will then work on Layer 2, Layer 3, and so on. The Trouble Tickets in Chapter 8, "Shooting Trouble with Frame Relay," covered Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), and Frame Relay troubles using multipoint and point-to-point subinterfaces. For a little variety, you will work with Enhanced Interior Gateway Routing Protocol (EIGRP) and Intermediate System-to- Intermediate System (IS-IS) on the WAN in this chapter.
Figure 9-1. Shooting Trouble on the WAN
NOTE
Do your homework up front if you plan to set up the ISDN labs. Unfortunately, there is no back-to-back cable plan for ISDN, so you need an ISDN switch or ISDN simulator of some type. Keep in mind that if your BRI ports are S/T, which most 2500 ports are, you need NT1s depending on the specific capabilities of your ISDN switch or simulator.
For more details, see the "ISDN BRI" section. One of the most economical solutions I found for a simulator is at www.cheapisdn.com.
The scenario goal is for you to modify your existing configuration or start from scratch to build a scenario that you can continue to build off of with the various WAN topics. Do that now using the
• 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 following guidelines. Add router 6 (r6), and redeploy r1 through r5 so that they are best utilized for the appropriate LAN and WAN interface requirements. Just remember to label your devices as in Figure 9-1 if you make any physical changes so that you can follow along with the chapter.
Connect r5s1 to r6s1 using a back-to-back serial cable. My r6 is a 2520. However, you can use whatever has the correct number of interfaces for the scenarios. It is preferred that r5 and r6 both have an ISDN BRI interface for later use. All data links should be using the default
encapsulation type to transport IP and EIGRP autonomous system 109. I am restricting you to subnet 0; 192.168.9.0/27 for now.
Draw a picture of the physical layout and label the pertinent items as in Figure 9-1. After the physical connectivity, configure all routers starting with r1. My instructions start from the ending configurations of Chapter 8. Change the routing protocol from OSPF to EIGRP, the encapsulation from Frame Relay to HDLC, and account for the new routers and addresses as in Example 9-1.
There is not always one right or wrong way to accomplish the tasks presented. The ability to obtain the end result using good practices is extremely important in any real-world network. My troubleshooting and device configurations are presented starting in Example 9-1 so that you can compare your work and perhaps see a different approach to obtaining the end result. Use the previous checklists, your step-by-step troubleshooting methodology, and the WAN checklist in Table 9-1 to assist in testing. Frame Relay is not included in this checklist but was covered back in Chapter 8.
Table 9-1. WAN Quick Troubleshooting Checklist
Isolating Problems Commands and
Symptoms Ping is a quick initial test for any troubleshooting. Extended ping
gives you more options.
ping
Trace is ping's companion test for connectivity and performance.
Extended trace gives you more options.
traceroute
Check Physical Layer status and clocking. show controllers s 0 show controllers bri 0 show controllers t 1
• 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
Check interface status and encapsulation. show ip interface brief show interfaces
[interface]
show interfaces s0 show interfaces bri0 [1 | 2]
show ip interfaces [interface]
show cdp neighbors [detail]
clear interface ? clear counters Monitor using date and time stamps for logging and debug
activity.
service timestamps debug datetime localtime msec
service timestamps log datetime localtime msec Are you communicating with the provider? Have you ever
communicated with the provider? If Layer 1 is deactivated, check your switch type configuration, SPIDs, and configuration.
show isdn status show dialer debug dialer
show dialer interface bri 0
show isdn history debug serial interface Check your Layer 2/Layer3 mapping. ISDN has its own Layer 2
and Layer 3. Layer 3 is for signaling and has nothing to do with the bearer payload being IP Layer 3.[*]
show dialer map show isdn status Analyze ISDN Layer 2 communications between you and the local
switch (local loop).
show isdn status debug isdn q921 Analyze ISDN Layer 3 activity (end-to-end signaling). show isdn status debug isdn q931
Verify end-to-end PPP authentication. debug ppp negotiation
debug ppp authentication
Verify configuration. show run interface bri0
Communicate with the service provider.
• 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
[*] Q931 deals with ISDN end-to-end call setup, but there is no Layer 3 address. The E.164 phone number would be like your MAC address on the LAN, which technically makes ISDN part of the Layer 2 data-link realm.
Example 9-1 illustrates the router configurations for r1 through r3 according to this chapter's section "Shooting Trouble on the WAN Scenario." Example 9-2 shows the same for r4 through r6.
Example 9-1. Shooting Trouble on the WAN r1 Through r3 Configuration
r1(config)#interface s0 r1(config-if)#shut
r1(config-if)#encap hdlc r1(config-if)#bandwidth 64
r1(config-if)#ip address 192.168.9.1 255.255.255.252 r1(config-if)#no shut
r1(config-if)#no router ospf 1 r1(config)#router eigrp 109
r1(config-router)#network 192.168.9.0 r1(config-router)#end
r1#copy running-config startup-config r2(config)#interface s0
r2(config-if)#shut
r2(config-if)#encap hdlc r2(config-if)#bandwidth 64
r2(config-if)#ip address 192.168.9.6 255.255.255.252 r2(config-if)#no shut
r2(config-if)#no router ospf 1 r2(config)#router eigrp 109
r2(config-router)#network 192.168.9.0 r2(config-router)#end
• 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 r2#copy running-config startup-config
frame-switch(config)#hostname r3 r3(config)#interface s0/0
r3(config-if)#shut
r3(config-if)#encap hdlc r3(config-if)#bandwidth 64 r3(config-if)#clock rate 64000
r3(config-if)#ip address 192.168.9.2 255.255.255.252 r3(config-if)#no shut
r3(config-if)#interface s0/1 r3(config-if)#shut
r3(config-if)#encap hdlc r3(config-if)#bandwidth 64 r3(config-if)#clock rate 64000
r3(config-if)#ip address 192.168.9.5 255.255.255.252 r3(config-if)#no shut
r3(config-if)#interface s0/2 r3(config-if)#shut
r3(config-if)#encap hdlc r3(config-if)#bandwidth 64 r3(config-if)#clock rate 64000
r3(config-if)#ip address 192.168.9.9 255.255.255.252 r3(config-if)#no shut
r3(config-if)#interface s0/3 r3(config-if)#shut
r3(config-if)#encap hdlc r3(config-if)#bandwidth 64 r3(config-if)#clock rate 64000
• 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 r3(config-if)#ip address 192.168.9.13 255.255.255.252
r3(config-if)#no shut
r3(config-if)#router eigrp 109
r3(config-router)#network 192.168.9.0 r3(config-router)#end
r3#copy running-config startup-config
Example 9-2. Shooting Trouble on the WAN r4 Through r6 Configuration
r4(config)#interface s0/0 r4(config-if)#shut
r4(config-if)#encap hdlc r4(config-if)#bandwidth 64
r4(config-if)#ip address 192.168.9.10 255.255.255.252 r4(config-if)#no shut
r4(config-if)#no router ospf 1 r4(config)#router eigrp 109
r4(config-router)#network 192.168.9.0 r4(config-router)#end
r4#copy running-config startup-config r5(config)#interface s0
r5(config-if)#shut
r5(config-if)#encap hdlc r5(config-if)#bandwidth 64
r5(config-if)#ip address 192.168.9.14 255.255.255.252 r5(config-if)#no shut
r5(config)#interface s1