Specifications

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
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Chapter 4 Configuring EIGRP
Licensing Requirements for EIGRP
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:
• Exchanging topology tables for the first time between two routers in startup mode.
• Advertising a topology table change.
• Sending a query message.
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 Chapter 11, “Configuring Layer 3
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:
Prerequisites for EIGRP
EIGRP has the following prerequisites:
• You must enable the EIGRP feature (see the “Enabling the EIGRP Feature” section on page 4-9).
Guidelines and Limitations
EIGRP has the following configuration guidelines and limitations:
• 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 13, “Configuring Route Policy Manager”).
Product License Requirement
Cisco NX-OS Full EIGRP requires a Enterprise Services license, however EIGRP stub 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.