Virtualization Support; Licensing Requirements For Eigrp; Prerequisites For Eigrp; Guidelines And Limitations - Cisco Nexus 3000 Series Configuration Manual

Chapter 4 Configuring EIGRP
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m
Split horizon is a method that controls the sending of EIGRP update and query packets. When you enable
split horizon on an interface, Cisco NX-OS does not send update and query packets for destinations that
were learned from this interface. Controlling update and query packets in this manner reduces the
possibility of routing loops.
Split horizon with poison reverse configures EIGRP to advertise a learned route as unreachable back
through that the interface that EIGRP learned the route from.
EIGRP uses split horizon or split horizon with poison reverse in the following scenarios:
•
•
•
By default, the split horizon feature is enabled on all interfaces.

Virtualization Support

Cisco NX-OS supports multiple instances of the EIGRP protocol that runs on the same system. EIGRP
supports Virtual Routing and Forwarding instances (VRFs). By default, Cisco NX-OS places you in the
default VRF unless you specifically configure another VRF. See
Virtualization."
By default, every instance uses the same system router ID. You can optionally configure a unique router
ID for each instance.

Licensing Requirements for EIGRP

The following table shows the licensing requirements for this feature:
Product License Requirement
Cisco NX-OS EIGRP requires a LAN Base Services license. For a complete explanation of the Cisco NX-OS licensing
scheme and how to obtain and apply licenses, see the Cisco NX-OS Licensing Guide.

Prerequisites for EIGRP

EIGRP has the following prerequisites:
•

Guidelines and Limitations

EIGRP has the following configuration guidelines and limitations:
•
•
Exchanging topology tables for the first time between two routers in startup mode.
Advertising a topology table change.
Sending a query message.
You must enable the EIGRP feature (see the
A metric configuration (either through the default-metric configuration option or through a route
map) is required for redistribution from any other protocol, connected routes, or static routes (see
Chapter 11, "Configuring Route Policy
For graceful restart, an NSF-aware router must be up and completely converged with the network
before it can assist an NSF-capable router in a graceful restart operation.
Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Chapter 9, "Configuring Layer 3
"Enabling the EIGRP Feature" section on page
Manager").
Licensing Requirements for EIGRP
4-9).
4-7