EIGRP - af-interface configuration mode
When configuring EIGRP in named mode, it is possible to configure EIGRP interface parameters from within the address-family configuration mode found under the router eigrp configuration mode.
This can be done using the af-interface command.
The command can be issued from the address-family configuration mode within the EIGRP router configuration. You can enter the configuration mode of all EIGRP interfaces on the router and issue commands for all of them, or you can choose individual interfaces to configure. For example, the following configuration sets all of the EIGRP interfaces to passive mode:
R1#configure terminal R1(config)#router eigrp MyEIGRP_AS R1(config-router)#address-family ipv4 vrf my_vrf autonomous-system 1 R1(config-router-af)#af-interface default R1(config-router-af-interface)#passive-interface R1(config-router-af-interface)#
The default keyword is used to indicate that the subsequent commands should be applied to all interfaces in that particular EIGRP address family.
The af-interface command also allows you to specify specific interfaces for which to apply EIGRP configuration parameters. The following commands change the EIGRP hold time for the GigabitEthernet0/1 interface:
R1#configure terminal
R1(config)#router eigrp MyEIGRP_AS
R1(config-router)#address-family ipv4 vrf my_vrf autonomous-system 1
R1(config-router-af)#af-interface gigabitethernet 0/1
R1(config-router-af-interface)#hold-time 10
R1(config-router-af-interface)#
You can achieve the same thing by going to each EIGRP interface and applying whatever EIGRP command you like, however, this makes it easier to do so directly from the configuration mode of the address family.
Links:
https://forum.networklessons.com/t/introduction-to-eigrp/881/188?u=lagapides