The Enhanced
Interior Gateway Routing Protocol (EIGRP) 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. We recommend that you upgrade to EIGRP named mode because all
new features, such as Wide Metrics, IPv6 VRF Lite, and EIGRP Route Tag
Enhancements, are available only in EIGRP named mode.
Use the
eigrp
upgrade-cli command to upgrade from classic mode to named mode.
You must use the
eigrp
upgrade-cli command for all classic router configurations to
ensure that these configurations are upgraded to the named mode. Therefore, if
multiple classic configurations exist, you must use this command per autonomous
system number. You must use this command separately for IPv4 and IPv6
configurations.
Prior to the EIGRP
Classic to Named Mode Conversion feature, upgrading to EIGRP named mode
required that the user manually unconfigure the classic mode using the
no router eigrp
autonomous-system-number command and then
reconfigure EIGRP configurations under named mode using the
router eigrp
virtual
name command. This method may lead to network churn and
neighborship or network flaps.
The EIGRP Classic to
Named Mode Conversion feature allows you to convert from classic mode to named
mode without causing network flaps or the EIGRP process to restart. With this
feature, you can move an entire classic mode configuration to a router named
mode configuration, and consequently, all configurations under interfaces will
be moved to the address-family interface under the appropriate address family
and autonomous-system number. After conversion, the
show
running-config command will show only named mode configurations;
you will not see any old classic mode configurations.