Download - 12.OSPF Troubleshooting
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7/28/2019 12.OSPF Troubleshooting
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Cisco CCNP ROUTE TrainingInstructor: Joe Rinehart, CCIE #14256
OSPFTroubleshooting
Cisco CCNP ROUTE Training
OSPF Troubleshooting
In This Lesson:
Troubleshooting Model
Common Issues and Resolution Steps
Relevant Debug and Show Commands
Dealing with Cisco TAC
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Troubleshooting Model
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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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Troubleshooting Model
Problem Resolution Methodology
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
1. Neighbor Relationship Problems
2. Routes Missing from Table
3. Address Summarization Problems
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
Possible Cause: Desired interfacesconfigured as passive
Alternatively execute the show ipprotocols and look for Passive-Interface(s) entry
Delete the passive-interfacecommand
Possible Cause: Misconfiguredneighbor authentication
Execute the show ip ospfinterface command to ifauthentication is in use
Frame Relay
WAN
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
Possible Cause: Misconfiguredneighbor authentication
Execute the show running-config command to verify that
both the ip ospf [key |message-digest-key] and ipospf authentication [message-digest] command are correct andin place and that keys match
Add either or both statements
with correct syntax if missing
Frame Relay
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
Possible Cause: Misconfigured MTUvalues on neighbor interfaces
Execute the show interfacecommand and note the MTUoutput on all/both neighbors
Enter interface configuration modeand equalize the MTU settingusing the ip mtu command and/or set to defaults
Frame Relay
WAN
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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806
708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
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
Frame Relay
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VLAN 910
R6
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R10R9
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Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
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 permitting224.0.0.5/6 is necessary
Execute show interface to
determine if interface is up/up
Replace cable or replaceinterface/device to resolve
Frame Relay
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Neighbor Not Establishing Relationship
Possible Cause: Network statementmisconfigured under OSPF
Execute the show ip OSPFinterface to discover if OSPF hascorrectly identified the interfaces
Execute the show running-config to verify that the networkstatements are correctlyconfigured in OSPF
Delete and recreate the networkstatements with the correctsubnet and mask combinations
Frame Relay
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Possible Cause: Non-Broadcast Network
Execute the show ip ospf interfaceto discover and note if the network
type under the Network Type entryis identified as NON_BROADCAST
Execute the show running-configcommand and verify if the neighbor command is present
If the statement is missing, add thestatic neighbor command on the DR/BDR routers
Frame Relay
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706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Neighbor Relationship Problems
Possible Cause: Priority 0 configured
Execute the show ip ospf neighborto verify the configured priority of theneighbor (1 is default)
If all neighbors are showing priority of
0, manually change the priority of thedesired DR/BDR
Possible Cause: Mismatched timers
Execute the show ip ospf interfaceand note the values of the Timer
Intervals entry (Hello XX, Dead XX)
Change values if they do not match
Frame Relay
WAN
607
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Routes Missing from Table
Possible Cause: Network statementmisconfigured under OSPF
Execute the show ip OSPF
interface to discover if OSPF hascorrectly identified the interfaces
Execute the show running-configto verify that the networkstatements are correctly configured inOSPF
Delete and recreate the network
statements with the correct subnetand mask combinations
Frame Relay
WAN
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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806
708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Routes Missing from Table
Possible Cause: Default routemisconfigured
Execute the show ip route to
discover if a static route to 0.0.0.0exists
Execute the show running-configto verify that the redistribute staticand default-information originate
statements are correctly configured inOSPF
Add the statements if they aremissing from the configuration
Frame Relay
WAN
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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708807
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Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Address Summarization Problems
Possible Cause: No subnets in the routingtable in the range of the summary
address
Execute the show ip routecommand to see if any networks
within the range currently exist
Execute the show running-configto verify that the ip area-rangeand/or summary-addressstatement is correctly configured
Delete and recreate the summary
statement with corrections and/or findthe cause of the missing route
Frame Relay
WAN
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
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708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Common Issues and Resolution Steps
Address Summarization Problems
Possible Cause: Routers reside in aStub/NSSA area
Execute the show ip route
command to see if any networkswithin the range currently exist
Execute the ip ospfstatement andlook for the statement It is a stubarea
This is normal behavior for stub areas(i.e., to suppress summary routes)
Either change the area type or verifyreachability of the area range orsummary address
Frame Relay
WAN
607
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
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708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
1. OSPF Show Commands
2. OSPF Debug Commands
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip protocols
Data displayed by the command
OSPF status and process-id
Area types configured
Protocols being redistributed
Networks being advertised
Neighbors/gateways
Helpful in troubleshooting:
Neighbor relationships
Missing routes
Summarization issues
Filtering problems
Frame Relay
WAN
607
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VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip route ospf
Data displayed by the command
OSPF routes from neighbors
Administrative distance
Cumulative cost metric
Route source/interface
Helpful in troubleshooting:
Missing routes
Summarization issues
Filtering problems
General troubleshooting
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip ospf interfaces
Data displayed by the command
Interfaces participating in OSPF
Network type(s)
Neighbor count
Authentication type
Timer values
Helpful in troubleshooting:
Neighbor relationships
Local configuration issues
Routing problems
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip eigrp neighbors
Data displayed by the command
Active fully adjacent neighbors
Router ID of neighbors
IP address/interface of neighbors
Dead time of neighbors
Neighbor state/DR state
Helpful in troubleshooting:
Neighbor relationships
Local configuration issues
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip ospf database
Data displayed by the command
LSA types per area
Advertising router
Link ID (subnet)
Age
Helpful in troubleshooting:
Missing routes
Filtering problems
General troubleshooting
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip ospf border-routers
Data displayed by the command
Router ID
Advertising router
Area
Whether an ABR or ASBR
Cost to reach
Helpful in troubleshooting:
Missing routes
Filtering problems
General troubleshooting
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Show Commands
show ip ospf
Data displayed by the command
OSPF process ID
Configured areas
Number/types of areas/ranges
Configured area authentication
Times SPF algorithm executed
Interfaces per area on router
Helpful in troubleshooting:
Missing routes
Filtering problems
General troubleshooting
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
OSPF Debug Commands
debug ip ospf adjacency
Debugging neighbor adjacencies
Helpful in troubleshooting:
Neighbor relationships
Routing update issues
Stub router problems
debug ip ospf events
Debugging network events
Helpful in troubleshooting:
Routing update issues
Convergence issues
Interface flapping
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79
OSPFArea 8
(Stub)
OSPF
Area 910
Backbone
?Cisco CCNP ROUTE Training
OSPF Troubleshooting
Relevant Debug and Show Commands
EIGRP Debug Commands
debug ip spf hello
Debugging neighbor adjacencies
Helpful in troubleshooting:
Neighbor relationships
Configuration issues
DR/BDR election problems
Frame Relay
WAN
607
706
VLAN 79
VLAN 910
R6
R7 R8
R10R9
608
806
708807
OSPF
Area 0
OSPF
Area 79OSPF
Area 8
(Stub)
OSPF
Area 910
Backbone?
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
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
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
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 SMARTNet
service contract
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
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)
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OSPF Troubleshooting
Dealing with Cisco TAC
Severity Levels
Severity 2 (S2): Operation of anexisting network or environment is
severely degraded, or significant aspectsof your business operation are negativelyaffected by inadequate performance ofCisco products. You and Cisco will commitfulltime resources during normal businesshours to resolve the situation
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
Severity Levels
Severity 3 (S3): Operationalperformance of your network orenvironment is impaired while most
business 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, or
configuration. There is little or no effecton your business operations
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
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
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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OSPF Troubleshooting
Dealing with Cisco TAC
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
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
Information to Have Ready
Very Helpful Information
Output from show tech command (ifapplicable) and all other relevant
output
Software versions and types ofequipment
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
Cisco CCNP ROUTE Training
OSPF Troubleshooting
Dealing with Cisco TAC
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
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Cisco CCNP ROUTE Training
OSPF Troubleshooting
Key Terms You Should Know
Cisco TAC Cisco Technical Assistance Center, the 24x7x365help desk support system for customers using Cisco products
S1 Severity TAC case severity in which the production
network is down and in a critical state needing immediateresolution
S2 Severity TAC case severity in which the production
network 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
Cisco CCNP ROUTE Training
OSPF Troubleshooting
What We Covered
Troubleshooting Model
Common Issues and Resolution Steps
Relevant Debug and Show Commands
Dealing with Cisco TAC