EIGRP Named Mode

Introduced in IOS release 15, the new the EIGRP Named Mode, also known as multi-af mode, streamlined the configuration of EIGRP as opposed to the old way of configuring it - the Classic Mode, also known as autonomous mode. It gathers all the configuration of interface parameters and such under the process configuration and introduces some new features.

Currently, the structuring of the commands are the main difference between Classic and Named Mode, but aside from all new features to come only being supported in multi-af mode, there are a few changes already.

Changes in Named Mode compared to Classic Mode includes some of the following:

• The Wide Metric is enabled causing the metric to be further scaled due to it being too large for what is allowed in the RIB
• The delay is now measured in picoseconds instead of microseconds
• Authentication now supports SHA-256 along with the old MD5
• SHA authentication does not support key chains and therefore do not support key rotation

The new multi-af (named) mode is fully compatible with the classic mode configuration and there is even a single command that will upgrade your configuration from the classic format to the new multi-af format. This is done by entering in the eigrp upgrade-cli <name> under the eigrp router process. Below is a configuration example of EIGRP configuration before and after the upgrade.

R1#show running-config | section router eigrp
router eigrp 100
 metric weights 0 0 0 1 0 0
 network 10.0.0.0 0.0.0.255
 network 192.168.0.1 0.0.0.0
 passive-interface Loopback0
R1#show running-config | section (interface (GigabitEthernet1|Loopback0))
interface Loopback0
 ip address 192.168.0.1 255.255.255.0
interface GigabitEthernet1
 ip address 10.0.0.1 255.255.255.0
 no ip split-horizon eigrp 100
 passive-interface Loopback0

As seen above, EIGRP has been configure with a non-default K-value configuration, two network statements and a passive-interface. Now, below the EIGRP will be upgraded from classic to named mode using the CLI command eigrp upgrade-cli <name> under the router process.

R1(config-router)#eigrp upgrade-cli NAMED_EIGRP
Configuration will be converted from router eigrp 100 to router eigrp NAMED_EIGRP.
Are you sure you want to proceed? ? [yes/no]: yes
R1(config)#
*Dec  1 12:42:23.769: EIGRP: Conversion of router eigrp 100 to router eigrp NAMED_EIGRP - Completed.

And now we verify the commands have been carried over from classic to named.

R1#show running-config | section router eigrp
router eigrp NAMED_EIGRP
 !
 address-family ipv4 unicast autonomous-system 100
  !
  af-interface Loopback0
   passive-interface
  exit-af-interface
  !
  af-interface GigabitEthernet1
   no split-horizon
  exit-af-interface
  !
  topology base
  exit-af-topology
  network 10.0.0.0 0.0.0.255
  network 192.168.0.1 0.0.0.0
  metric weights 0 0 0 1 0 0 0
 exit-address-family

Now, all the commands that were scattered across the enabled interfaces and the router process has been put under the named mode router config. Namely, the passive-interface for loopback0, which was under the router process in classic mode, and the no split-horizon, which was under the gigabitethernet1 interface in classic mode.

There is a little shortcut in Cisco IOS worth mentioning, when working with named mode, that will shorten the command address-family ipv4 unicast autonomous-system 100 into a much more manageable address-family ipv4 as 100 command. This omits the unicast parameter and shortens autonomous-system to as.

The new command structure may seem a bit confusing at first, but when you need to configure, lets say, default authentication on all EIGRP enabled interfaces - or maybe set the Hello and Hold timers - you will love the af-interface default section of the multi-af configuration.