# EIGRP summary

Basic

Router(config)#router eigrp 65000
Router(config-router)#network 192.168.0.0 0.0.255.255
Router(config)#ip default-network 192.168.1.0
Router(config-router)#passive-interface default
Router(config-router)#no passive-interface Ethernet0

Summarization

Router(config-router)# ! Transmit subprefix information
Router(config-router)#no auto-summary
Router(config-if)# ! Manual summarization
Router(config-if)#ip summary-address eigrp 65000 172.16.0.0 255.255.0.0

Load balancing

Router(config-router)# ! Unequal cost path load balancing
Router(config-router)# ! Metric < 2*best_metric
Router(config-router)#variance 2
Router(config-router)# ! Proportionately to the ratios of the metrics
Router(config-router)#traffic-share balanced

Bandwidth utilization

Router(config-if)#bandwidth 100000
Router(config-if)# ! 25Mbps for EIGRP traffic (default 50%)
Router(config-if)#ip bandwidth-percent eigrp 65000 25

Stub routing

HubRouter(config-router)#eigrp stub
HubRouter(config-router)#neighbor 192.168.1.1 Ethernet 0
SpokeRouter(config-router)#no ip split-horizon 65000
SpokeRouter(config-router)#neighbor 192.168.1.2 Ethernet 0

Timers

Router(config-if)#ip hello-interval eigrp 65000 2
Router(config-if)#ip hold-time eigrp 65000 8 ! ~ 3*hello-interval

Authentication

Router(config-if)#ip authentication mode eigrp 65000 md5
Router(config-if)#ip authentication key-chain eigrp 65000 eigrp_key

Verification

Router#show ip eigrp neighbors
Router#show ip eigrp topology
Router#show ip eigrp traffic
Router#debug ip eigrp packet
Router#debug ip eigrp neighbors
Router#debug ip eigrp summary
Router#debug ip eigrp