This document discusses advanced EIGRP configuration and troubleshooting. It covers EIGRP auto-summarization and how to disable it, verifying auto-summarization, configuring manual summarization, bandwidth control, hello and hold timers, and basic troubleshooting commands. Configuration examples are provided for manual summarization and bandwidth control.

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8- Advanced EIGRP Configuration &
Troubleshooting
8.1 Advanced EIGRP Configuration and Troubleshooting

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8.1 Advanced EIGRP Configuration and
Troubleshooting

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EIGRPAUTOSUMMARIZATION
• EIGRP automatically advertises
summary routes to other EIGRP
routers
• Disabled after Cisco IOS Release
15.0(1)M
• Can be disabled manually with
"no auto-summary" command
R1 R2
10.41.1.210.41.1.1
Gig 0/0 Gig 0/0
172.16.14.0/24
172.16.0.0/16

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VERIFYINGEIGRPAUTOSUMMARIZATION

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VERIFYINGEIGRPAUTOSUMMARIZATION

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VERIFYINGEIGRPAUTOSUMMARIZATION

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EIGRPMANUALSUMMARIZATION
• EIGRP automatically summarizes
networks at the classful boundary
• Can cause problems i.e. you could have
two routers advertise the same network—
172.16.0.0/16—when in fact they wanted
to advertise two different networks—
172.16.10.0/24 and 172.16.20.0/24
• Proper solution : Turn off auto sum. And
use manual summarization if necessary
R1 R2
10.41.1.210.41.1.1
Gig 0/0 Gig 0/0
10.21.0.0/16
10.20.0.0/14

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CONFIGURINGEIGRPMANUALSUMMARIZATION
R1 R2
10.41.1.210.41.1.1
Gig 0/0 Gig 0/0
10.21.0.0/16
10.20.0.0/14

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CONFIGURING IPv6EIGRPMANUALSUMM.

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CONFIGURINGEIGRPBANDWIDTHCONTROL
• By default, EIGRP will limit itself to using no more
than 50% of the interface bandwidth
• This value can be modified by network administrator

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CONFIGURINGHELLO&HOLDTIMERS
• It is possible for two routers to become EIGRP neighbors even though
the hello and hold timers do not match ( Unstable adjacency )
• Default Hello = 5 seconds , Hold : Three times the hello interval
(Default 15 seconds)
• If hello interval is changed, hold time is NOT automatically changed.
Must be configured manually

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STEPBY STEPEIGRPTROUBLESHOOTING
• Check interface IP addresses
and subnet masks
• Check EIGRP AS numbers
• Check network statements
• Check passive interfaces

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BASICEIGRPTROUBLESHOOTINGCOMMANDS