Overview

About Interfaces

Cisco NX-OS supports multiple configuration parameters for each of the interface types supported. Most of these parameters are covered in this guide but some are described in other documents.

The following table shows where to get further information on the parameters you can configure for an interface.

Table 1 Interface Parameters

Feature

Parameters

Further Information

Basic parameters

description, duplex, error disable, flow control, MTU, beacon

“Configuring Basic Interface Parameters”

Layer 3

medium, IPv4 and IPv6 addresses

“Configuring Layer 3 Interfaces”

Layer 3

bandwidth, delay, IP routing, VRFs

Cisco Nexus 9000 Series NX-OS Unicast Routing Configuration Guide

Cisco Nexus 9000 Series NX-OS Multicast Routing Configuration Guide

Port Channels

channel group, LACP

“Configuring Port Channels”

Security

EOU

Cisco Nexus 9000 Series NX-OS Security Configuration Guide

Ethernet Interfaces

Ethernet interfaces include routed ports.

Access Ports

An access port carries traffic for one VLAN. This type of port is a Layer 2 interface only.

For more information on routed ports, see the “Information About Access and Trunk Interfaces” section.

Routed Ports

A routed port is a physical port that can route IP traffic to another device. A routed port is a Layer 3 interface only.

For more information on routed ports, see the “Routed Interfaces” section.

Management Interface

You can use the management Ethernet interface to connect the device to a network for remote management using a Telnet client, the Simple Network Management Protocol (SNMP), or other management agents. The management port (mgmt0) is autosensing and operates in full-duplex mode at a speed of 10/100/1000 Mb/s.

For more information on the management interface, see the Cisco Nexus 9000 Series NX-OS Fundamentals Configuration Guide. You will also find information on configuring the IP address and default IP routing for the management interface in this document.

Port-Channel Interfaces

A port channel is a logical interface that is an aggregation of multiple physical interfaces. You can bundle up to 32 individual links to physical ports into a port channel to improve bandwidth and redundancy. You can also use port channeling to load balance traffic across these channeled physical interfaces. For more information about port-channel interfaces, see the “Configuring Port Channels” section.

Subinterfaces

You can create virtual subinterfaces on a parent interface configured as a Layer 3 interface. A parent interface can be a physical port. Subinterfaces divide the parent interface into two or more virtual interfaces on which you can assign unique Layer 3 parameters such as IP addresses and dynamic routing protocols.

Loopback Interfaces

A virtual loopback interface is a virtual interface with a single endpoint that is always up. Any packet that is transmitted over a virtual loopback interface is immediately received by that interface. Loopback interfaces emulate a physical interface. For more information about subinterfaces, see the “Loopback Interfaces” section.

Breakout Interfaces

Cisco NX-OS supports the breakout of high bandwidth 40G interfaces at the module level or at the per-port level.


Note

The breakout of high bandwidth interfaces (module level or per-port level) are supported only on:

  • The X9636PQ, X9432PQ, and X9536PQ line cards on a Cisco Nexus 9500 Series switch.

  • The Cisco Nexus 9332PQ switch.

  • The Cisco Nexus 3164Q switch.

Module Level Breakout

For module level breakout, the interface breakout command splits the high bandwidth 40G interface of a module into four 10G interfaces. The module is reloaded and the configuration for the interface is removed when the command is executed.

The following is an example of the command: 

switch# configure terminal
switch(config)# interface breakout module 1
Module will be reloaded. Are you sure you want to continue(yes/no)? yes

The no interface breakout module module_number command undoes the breakout configuration. It puts all interfaces of the module in 40G mode and deletes the configuration for the previous 10G interfaces.

Dynamic Breakout (Per-port Level Breakout)

For dynamic breakout (per-port level breakout), the interface breakout command splits high bandwidth 40G ports into four 10G breakout ports. The breakout ports are identified as Ethernet <slot>/<front-panel-port>/<breakout-port>. For example, per-port level breakout ports can be identified as Ethernet 1/2/1, Ethernet 1/2/2, Ethernet 1/2/3, and Ethernet 1/2/4.

When one or more 40G interfaces of the module are broken-out at the per-port level, the configuration for the interfaces are removed when the command is executed.


Note

A per-port level breakout does not require the module to be reloaded.

The following is an example of configuring a breakout port: 

switch(config)# interface breakout module 1 port 1 map 10g-4x
switch(config)#

The following is an example of configuring a multiple breakout ports: 

switch(config)# interface breakout module 1 port 1-4 map 10g-4x
switch(config)#

You can undo the breakout ports with the no interface breakout command.

The following is an example to undo the breakout ports: 

switch(config)# no interface breakout module 1 port 1 map 10g-4x
switch(config)#

Virtual Device Contexts

Cisco NX-OS can segment operating system and hardware resources into virtual device contexts (VDCs) that emulate virtual devices. The Cisco Nexus 9000 Series switch does not support multiple VDCs. All switch resources are managed in the default VDC.

High Availability for Interfaces

Interfaces support stateful and stateless restarts. A stateful restart occurs on a supervisor switchover. After the switchover, Cisco NX-OS applies the runtime configuration.