The Enhanced Interior Gateway Routing Protocol can be configured using either the classic mode or the named mode. The classic mode is the old way of configuring EIGRP. In classic mode, EIGRP configurations are scattered across the router mode and the interface mode. The named mode is the new way of configuring EIGRP; this mode allows EIGRP configurations to be entered in a hierarchical manner under the router mode.
Each named mode configuration can have multiple address families and autonomous system number combinations. In the named mode, you can have similar configurations across IPv4 and IPv6.
Although Named EIGRP is configured differently from traditional EIGRP, the configurations are compatible, meaning that an EIGRP-speaking router configured with the traditional approach can form a neighborship with an EIGRP-speaking router configured with the Named approach.
There are three configuration modes in named EIGRP:
- Address-Family: to configure networks, EIGRP neighbor, EIGRP Router-id, metric etc.
- Address-Family-Interface: to configure all the interface specific commands that were previously configured on an actual interface (logical or physical) and moves them into the EIGRP configuration. For instance EIGRP authentication, split-horizon, summary-address configuration etc.
- Address-Family-Topology: to provide several options which operates on EIGRP topology table. For instance redistribution, distance, offset list, variance etc.
To better understand how named EIGRP works suppose that you want convert this classic eigrp configuration to the named eigrp configuration.
Classic EIGRP configuration
int Gi0/0 ip add 192.168.1.1 255.255.255.252 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 ciscozine-key ip hello eigrp 100 12 ipv6 address 2003::1/64 ipv6 eigrp 200 router eigrp 100 network 192.168.1.0 0.0.0.3 passive-interface default no passive-interface Gi0/0 distribute-list prefix Ciscozine-PREFIX in redistribute connected ipv6 router eigrp 200 variance 2 router eigrp 300 address-family ipv4 vrf Cisco-VRF network 0.0.0.0 0.0.0.0
Named EIGRP configuration
router eigrp Ciscozine address-family ipv4 unicast autonomous-system 100 network 192.168.1.0 0.0.0.3 af-interface default passive-interface exit-af-interface af-interface Gi0/0 no passive-interface authentication mode md5 authentication key-chain ciscozine-key hello-interval 12 exit-af-interface topology base redistribute connected distribute-list prefix Ciscozine-PREFIX in exit-af-topology exit-address-family address-family ipv6 unicast autonomous-system 200 topology base variance 2 exit-af-topology exit-address-family address-family ipv4 unicast vrf Cisco-VRF autonomous-system 300 network 0.0.0.0 0.0.0.0 exit-address-family
Remember: Even though Named EIGRP is configured differently than traditional EIGRP, the show commands remain the same.
Note: The EIGRP named configuration is available from these releases:
- Cisco IOS XE Release 2.5
Note: From IOS 15.4(2)T or IOS XE 3.11S, Cisco has introduced the “eigrp upgrade-cli” command. This feature permits to upgrade EIGRP “classic mode” configurations to named mode without causing network flaps or requiring EIGRP process restart. After conversion, the show running-config command will show only named mode configurations; you will not see any old classic mode configurations.