Specifications

Send document comments to [e-mail].
2-6
Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
OL-25782-02
Chapter 2 Configuring IPv4
Licensing Requirements for IPv4
ICMP
You can use ICMP to provide message packets that report errors and other information that is relevant
to IP processing. ICMP generates error messages, such as ICMP destination unreachable messages,
ICMP Echo Requests (which send a packet on a round trip between two hosts) and Echo Reply messages.
ICMP also provides many diagnostic functions and can send and redirect error packets to the host. By
default, ICMP is enabled.
Some of the ICMP message types are as follows:
• Network error messages
• Network congestion messages
• Troubleshooting information
• Timeout announcements
Note ICMP redirects are disabled on interfaces where the local proxy ARP feature is enabled.
Virtualization Support
IPv4 supports Virtual Routing and Forwarding instances (VRFs). By default, Cisco NX-OS places you
in the default VRF unless you specifically configure another VRF. For more information, see
Chapter 11, “Configuring Layer 3 Virtualization.”
Licensing Requirements for IPv4
The following table shows the licensing requirements for this feature:
Prerequisites for IPv4
IPv4 has the following prerequisites:
• IPv4 can only be configured on Layer 3 interfaces.
Guidelines and Limitations
IPv4 has the following configuration guidelines and limitations:
• You can configure a secondary IP address only after you configure the primary IP address.
Product License Requirement
Cisco NX-OS IPv4 requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS
system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS
licensing scheme, see the Cisco NX-OS Licensing Guide.