07.EIGRP Troubleshooting

8/11/2019 07.EIGRP Troubleshooting

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Cisco CCNP ROUTE TrainingInstructor: Joe Rinehart, CCIE #14256

EIGRP Troubleshooting

Cisco CCNP ROUTE Training


In This Lesson:

Troubleshooting Model

Common Issues and Resolution Steps

Relevant Debug and Show Commands

Dealing with Cisco TAC




1. Define the Problem

2. Gather the Facts

3. Document the Facts

4. Consider the Possibilities

5. Create an Action Plan

6. Implement the Action Plan

7. Repeat Until Resolution

8. Document the Solution


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Problem Resolution Methodology




1. Neighbor Relationship Problems

2. Routes Missing from Table

3. Address Summarization Problems




Neighbor Relationship Problems

Neighbor Not Establishing Relationship

Possible Cause: Mismatched K Values

Execute the show ip protocolscommand on the affected devices

Examine the output under theeigrp metric weight line andnote the values

Use the metric weightscommand in router configurationmode to change values if required

Possible Cause: Mismatched ASN

Examine the configuration ofaffected devices for the ASN


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Possible Cause: Mismatched ASN

Alternatively execute the show ipprotocols to find ASN

Delete and restart the EIGRP

process using the correct ASN

Possible Cause: Misconfiguredneighbor authentication

Execute the show key chaincommand to verify key string andaccept/send lifetime settings

Reconfigure correct string ifneeded






Possible Cause: Misconfiguredneighbor authentication

Execute the show running-config command to verify thatboth the ip authentication key-chain and ip authenticationmode command are correct andin place

Add either or both statements

with correct syntax if missing






Possible Cause: Primary subnets notmatching

Execute the show ip interface command to verifythe primary IP address configuredon the interfaces of affecteddevices

Change IP addressing if primarysubnets are not on the samenetwork/subnet


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Possible Cause: Multicast traffic beingblocked between devices

Execute the show ip interfaceand show access-list command

to discover if any filtering is beingdone on the affected interfaces

Add statements permitting224.0.0.10 is necessary

Execute show interface to

determine if interface is up/up

Replace cable or replaceinterface/device to resolve






Possible Cause: Network statementmisconfigured under EIGRP

Execute the show ip eigrpinterface to discover if EIGRP hascorrectly identified the interfaces

Execute the show running-config to verify that the networkstatements are correctlyconfigured in EIGRP

Delete and recreate the networkstatements with the correctsubnet and mask combinations




Routes Missing from Table

Possible Cause: Split Horizon is In Effecton a Multipoint Interface

Execute the show running-config

to discover if the no split-horizoneigrp statement isconfigured

Enter interface configuration mode onthe multipoint/natural interface and

amend the configuration

If the statement is present, verify thatthe ASN is correct and amend if thereis a discrepancy


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Possible Cause: Automatic networksummarization is in effect

Execute the show running-configto discover if the no auto-summarystatement is configured under EIGRP

Use the show ip protocols commandand look for the statementAutomatic networksummarization is/not in effect

If automatic network summarizationis in effect, execute the no auto-

summary command in eigrp routerconfiguration mode





Possible Cause: Network statementmisconfigured under EIGRP

Execute the show ip eigrp

interface to discover if EIGRP hascorrectly identified the interfaces

Execute the show running-configto verify that the networkstatements are correctly configured inEIGRP

Delete and recreate the network

statements with the correct subnetand mask combinations




Address Summarization Problems

Possible Cause: No Subnets in theRouting Table in the Range of theSummary Address

Execute the show ip routecommand to see if any networkswithin the range currently exist

Execute the show running-configto verify that the ip summary-

address eigrp statement is correctlyon the interface (network, ASN, etc.)

Delete and recreate the summarystatement with corrections and/or findthe cause of the missing route


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1. EIGRP Show Commands

2. EIGRP Debug Commands




EIGRP Show Commands

show ip protocols

Data displayed by the command

EIGRP status and ASN

Configured K-Values

Protocols being redistributed

Networks being advertised

Neighbors/gateways

Helpful in troubleshooting:

Neighbor relationships

Missing routes

Summarization issues

Filtering problems




EIGRP Show Commands

show ip route eigrp


EIGRP routes from neighbors

Feasible distance metric

Route source/interface


Missing routes

Summarization issues

Filtering problems

General troubleshooting


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EIGRP Show Commands

show ip eigrp interfaces


Interfaces participating in EIGRP

Number of neighbors on aninterface

EIGRP ASN in use



Local configuration issues

Routing problems




EIGRP Show Commands

show ip eigrp neighbors


Active fully adjacent neighbors

IP address/interface of neighbors

Holdtime of neighbors

EIGRP ASN in use



Local configuration issues




EIGRP Show Commands

show ip eigrp topology


Complete listing of the EIGRPtopology database

Status of routes (active/passive)

Feasible/Reported distance metric

Successors/Feasible Successor


Missing routes

Stuck-in-Active problems

Filtering problems

General troubleshooting


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EIGRP Debug Commands

debug eigrp packet

Types supported

Hello

Update

Query/Reply

ACK

Stub



Routing update issues


Stub router problems




EIGRP Debug Commands

debug ip eigrp

Information provided

EIGRP routing events

Routing table events

Update processing



Routing update issues





1. Understanding TAC

2. Severity Levels

3. Opening a TAC Case

4. Information to Have Ready:

5. Working the Case Actively

6. TAC Case Etiquette


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Understanding TAC

24x7x365 coverage for all Cisco productlines

Located worldwide (primary sites):

San Jose, CA

Sydney, Australia

Raleigh, NC

Brussels, Belgium

Attachment to open cases

Entitlement tied to valid SMARTNetservice contract




Severity Levels

Severity 1 (S1): Your network orenvironment is down or there is acritical impact to your business

operations. You and Cisco will commit allnecessary resources around the clock toresolve the situation (use care whendesignating a situation as an S1, useescalation if resolution for S2/S3 is notproceeding as you need it to)




Severity Levels

Severity 2 (S2): Operation of anexisting network or environment isseverely degraded, or significant aspects

of your business operation are negativelyaffected by inadequate performance ofCisco products. You and Cisco will commitfulltime resources during normal businesshours to resolve the situation


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Severity Levels

Severity 3 (S3): Operationalperformance of your network or

environment is impaired while mostbusiness operations remain functional.You and Cisco are willing to commitresources during normal business hoursto restore service to satisfactory levels

Severity 4 (S4):You requireinformation or assistance with Ciscoproduct capabilities, installation, orconfiguration. There is little or no effect

on your business operations




Opening a TAC Case

By E-mail: [email protected]

On the web:http://www.cisco.com/techsupport/servic

erequest

By Phone:

Asia Pacific +61 2 8446 7411

Australia 1 800 805 227

New Zealand 0800 44 6237

Europe +32 2 704 5555

US/Canada 1 800 553 2447




Information to Have Ready:

Must-Have Information:

Cisco Service Contract #

Product/Chassis Serial #

Product Model #/HW config

Physical location of the product

Severity Level of the Issue

Very Helpful Information:

Accurate description of the issue (andsuccinct case title)

History of the problem

Network topology and explanation
mailto:[email protected]://www.cisco.com/techsupport/servicerequesthttp://www.cisco.com/techsupport/servicerequesthttp://www.cisco.com/techsupport/servicerequesthttp://www.cisco.com/techsupport/servicerequestmailto:[email protected]


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Information to Have Ready:

Very Helpful Information:

Output from show tech command (ifapplicable) and all other relevantoutput

Software versions and types of

equipment

Relevant syslog/TACACS+ logs beforethe issue occurred

Working the Case Actively:

Send updates & information as requested

Maintain regular communication

Close the case when the issue is resolved




TAC Case Etiquette:

Treat the support engineer with courtesyand respect

Realize that TAC is not a substitute for

on-site staff

Create separate TAC cases for each issueunless clearly linked

Realize that you have control over theseverity level

Escalate to the TAC duty manager is youneed to move the case along

Pass along compliments to the supportengineers supervisor



Key Terms You Should Know

Cisco TAC Cisco Technical Assistance Center, the 24x7x365

help desk support system for customers using Cisco productsS1 Severity TAC case severity in which the production

network is down and in a critical state needing immediate

resolution

S2 Severity TAC case severity in which the productionnetwork is severely degraded with regards to performance

S3 Severity TAC case severity in which the productionnetwork is impaired but relatively functional

S4 Severity TAC case severity in which the productionnetwork is fully operational but assistance with information,configuration/installation guidance is required


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What We Covered

Troubleshooting model

Common issues and resolution steps

Relevant debug and show commands


Documents

07.EIGRP Troubleshooting