Tài liệu Remote ISDN Site not Answering doc

Scenario: The London network administrator informs you that there is no WAN connectivity.. ISDN connectivity has been lost between London and San Jose.. Based on logs maintained in San

1-2 Semester 8 Internetwork Troubleshooting v1.0 - Lab 9.2.4 Copyright  2001, Cisco Systems, Inc

Lab 9.2.4: Remote ISDN Site not Answering

ISDN

Atlas 550 192.168.16.0/24

BRI0/0 51055512340001 51055512350001

BRI0/0 51055540000001 51055540010001

Objective:

Establish an ISDN BRI to ISDN BRI call from a branch office to a central site

Scenario:

The London network administrator informs you that there is no WAN

connectivity ISDN connectivity has been lost between London and San Jose After some investigation you contact the San Jose administrator Based on logs maintained in San Jose, there has not been a successful ISDN session since yesterday when a security audit was performed

Though International Travel Agency (ITA) does not rely on sensitive “top-secret” information, the database of customer information has to be kept confidential Also, the integrity of the reservation systems is mission-critical Partners and customers need access to information, but the ability to modify information must be restricted and monitored

Step 1

Cable the lab as shown in the diagram

Load the Lab9-2-4-London-BrokenConfig.txt and Lab9-2-4-SanJose3-BrokenConfig.txt configuration files

Step 2

Start by turning on debug dialer and debug isdn events while

attempting to ping London from SanJose3

Is the call being connected?

2-2 Semester 8 Internetwork Troubleshooting v1.0 - Lab 9.2.4 Copyright  2001, Cisco Systems, Inc

Step 3

Gather more information by attempting an ISDN session with PPP specific debugging turned on

SanJose3#undebug all

All possible debugging has been turned off

SanJose3#debug ppp authentication

PPP authentication debugging is on

SanJose3#debug ppp negotiation

PPP protocol negotiation debugging is on

London#undebug all

All possible debugging has been turned off

London#debug ppp authentication

PPP authentication debugging is on

London#debug ppp negotiation

PPP protocol negotiation debugging is on

London#ping SanJose3

Step 4

Based on the output of the previous commands, what are some

possible reasons an ISDN call cannot be established between

London and SanJose3?

What is your action plan to resolve the problem and establish ISDN

connectivity between London and SanJose3?

Step 5

Implement your action plan and observe results by attempting an ISDN session

Step 6

Document your work with summary of problem, troubleshooting methods and resolution