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.
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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 access 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.
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 and 100G ports into four 25G 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)#
The following is an example of configuring 40G and 10G interfaces mixed together.
switch(config-if)# show int eth1/49 transceiver
Ethernet1/49
transceiver is present
type is QSFP-40G-SR-BD
name is CISCO-AVAGO
part number is AFBR-79EBPZ-CS2
revision is 01
switch(config-if)# show int eth1/52 transceiver
Ethernet1/52
transceiver is present
type is QSFP-Cazadero
name is CISCO-DNI
part number is CAZADERO-R
revision is 03
nominal bitrate is 10000 MBit/sec per channel
switch(config-if)# show int eth1/53 transceiver
Ethernet1/53
transceiver is present
type is QSFP-Cazadero
name is CISCO-DNI
part number is CAZADERO-R
revision is 03
nominal bitrate is 10000 MBit/sec per channel
switch(config)# interface breakout module 1 port 52-53 map 10g-4x
switch(config-if)# show int br | i up
mgmt0 -- up 10.122.160.192 100 1500
Eth1/49 -- eth routed up none 40G(D) — << Running 40G
Eth1/50 -- eth routed up none 40G(D) --
Eth1/52/1 -- eth routed up none 10G(D) — << Broken out to 10G
Eth1/53/1 -- eth routed up none 10G(D) -- << Broken out to 10G
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)#
About the Lane Selector
The lane selector is a push button switch and 4 LEDs located on the Cisco Nexus switch (left side of front panel, labeled "LS"). The push button switch and LEDs are used to indicate the status of the ports. The lane selector is supported on Cisco Nexus Series 9000 series switches and the Cisco Nexus 3164 and 3232 switches.
By default, the LEDs indicate the link/activity status of a 1 x 40G configuration. When the ports are configured as 4 x 10G, you can access the link status of each individual 10G port with the lane selector.
By pressing the lane selector push button, the port LED shows the selected lane’s link/activity status. The 1st time the push button is pressed, the first LED displays the status of the first port. Pressing the push button a 2nd time displays the status of the second port, and so on. You can display the status of each of the four ports by pressing the push button in this manner.
For example, if port 60 is configured as 4 x 10G, pressing the lane selector push button once displays the link status of 60/1/1. Pressing the push button a second time displays the link status of 60/1/2.
When you press the push button after displaying the status of the last port, all four of the LEDs should extinguish to indicate that the lane selector has returned to display the status for the default 1 x 40G configuration.
Note |
A 10G breakout port's LED blinks when the beacon feature has been configured for it. |
Note |
When a port is configured to be in 10G breakout mode and no lane is selected, the 40G port's LED illuminates as green even though only one of the 10G breakout ports is up. |
Notes About Breakout Interfaces
Beginning with Cisco NX-OS Release 7.0(3)F2(1), the 36-port 100-Gigabit Ethernet QSFP28 line cards (N9K-X9636C-R) and 36-port 40-Gigabit Ethernet QSFP+ line cards (N9K-X9636Q-R) provide 4x10-Gigabit support.
Beginning with Cisco NX-OS Release 9.2(1), N9K-9636C-R, N9K-X9636Q-R and N9K-X9636C-RX line cards support breaking out 40G ports into 4x10 Gigabits.
Caveats
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As of Cisco NX-OS Release 7.0(3)I7(2), manual breakout of QSA ports is not supported.
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When a break-out port is configured as a part of a port-channel, you need to apply the configuration twice (after write-erase/reload), to ensure the effectiveness of the port-channel.
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When you upgrade a Cisco Nexus 9000 device to Cisco NX-OS Release 7.0(3)I7(2) or later, if a QSFP port is configured with the manual breakout command and is using a QSA, the configuration of the interface Ethernet 1/50/1 is no longer supported and will need to be removed. To restore the configuration, you must manually configure the Ethernet 1/50 on the device.
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Cisco Nexus 9000 Series switches have 40G ports. When you breakout one of the 40G ports into 4x10G ports with a QSFP breakout cable, not all of the subinterfaces can be added to a port channel. The following error message is displayed:
switch# channel-group 99 mode active command failed: port not compatible [Buffer boost]
Note
As a workaround, configure no buffer-boost on all of the subinterfaces. This enables the channel-group configuration to go through.
Using the force keyword on the port-channel does not enable all the interfaces to be added to the port-channel even though the error message suggests using the keyword.
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Cisco Nexus 9000 switches defaults to FC-FEC mode while the FC-FEC mode is turned off on N9K-X9636C-RX line cards, by default. To enable interoperability between two such devices, you may need to manually change the FEC settings to match with each other.
High Bandwidth Interfaces
The breakout of high bandwidth interfaces (module level or per-port level) are supported only on:
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The X9636PQ, X9432PQ, X9536PQ, and X9732C-EX line cards on a Cisco Nexus 9500 Series switch.
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The Cisco Nexus 9332PQ switch.
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The Cisco Nexus 3164Q switch.
Cisco Nexus C92160YC Switch
For 7.0(3)I3(1) and later, the Cisco Nexus C92160YC switch provides two different modes of operation:
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Mode 1: 48 * 10G/25G + 4 * 40G + 2 * 100G (Default configuration)
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Hardware profile portmode 48x25G + 2x100G + 4x40G
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Breakout is supported in 2 * 100G ports
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Mode 2: 48 * 10G/25G + 4 * 100G
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Hardware profile portmode 48x25G + 4x100G
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Breakout is supported on 4 * 100G ports.
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Use the show running-config | grep portmode command to display the current operation mode.
Example:
switch(config-if-range)# show running-config | grep portmode
hardware profile portmode 48x25G+2x100G+4x40G
See the installation guide for the Cisco Nexus C92160YC switches for more information. ( Install and Upgrade Guides for Cisco Nexus 9000 Series Switches )
With the Cisco Nexus C92160YC switch , there are two breakout modes:
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40G to 4x10G breakout ports
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Enables the breakout of 40G ports into 4 X 10G ports.
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Use the interface breakout module 1 port x map 10g-4x command.
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100G to 4x25G breakout ports
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Enables the breakout of 100G ports into 4 X 25G ports.
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Use the interface breakout module 1 port x map 25g-4x command.
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Cisco Nexus C9272Q Switch
For 7.0(3)I3(1) and later, the Cisco Nexus C9272Q Switch provides 72 40G ports. Ports 37 - 71 support breakout interfaces.
To configure a breakout interface, use the interface breakout module 1 port x map 10g-4x command.
Example:
switch(config)# interface breakout module 1 port 38 map 10g-4x
switch(config)# show interface ethernet 1/38 capabilities | grep -i break
Breakout capable: yes
Cisco Nexus C9332PQ Switch
For 7.0(3)I3(1) and later, the Cisco Nexus C9332PQ Switch provides 24 40G ports that support breakout mode and can be connected to four 10G NIF ports on a FEX. Ports 1 - 12 and 15 - 26 ports are supported. (Ports 13 and 14 ports are reserved and cannot be used for breakout mode.)
Note |
All FEXs are supported. |
Note |
Only the Cisco Nexus 9332PQ switch provides interface breakout support for FEX fabric interfaces. (7.0(3)I3(1) and later) |
Cisco Nexus 9000 C93180LC-EX Switch
For 7.0(3)I7(1) and later, Cisco Nexus 9000 C93180LC-EX switch provides three different modes of operation:
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Mode 1: 28 x 40G + 4 x 40G/100G (Default configuration)
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Hardware profile portmode 4x100g + 28x40g.
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10x4 breakout is supported on the top ports from 1 to 27 (ports 1,3,5, 7...27). If any of the top port is broken out, the corresponding bottom port becomes non-operational. For example, if port 1 is broken out port 2 becomes non-operational.
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1 Gigabit and 10 Gigabit QSA is supported on ports 29, 30, 31, and 32. However, QSAs on the top and bottom front panel ports must be of same speed.
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Ports 29, 30, 31, and 32 support 10x4, 25x4, and 50x2 breakout.
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Mode 2: 24 x 40G + 6 x 40G/100G
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Hardware profile portmode 6x100g + 24x40g.
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10x4 breakout is supported on the top ports from 1 to 23 (ports 1,3,5, 7...23). If any of the top port is broken out the corresponding bottom port becomes non-operational.
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Ports 25, 27, 29, 30, 31, and 32 support 10x4, 25x4, and 50x2 breakout.
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1 Gigabit and 10 Gigabit QSA is supported on ports 29, 30, 31, and 32. However, QSAs on the top and bottom front panel ports must be of same speed.
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Mode 3: 18 x 40G/100G
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Hardware profile portmode 18x100g.
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10x4, 25x4, and 50x2 breakout is supported on top ports from 1 to 27 (ports 1,3,5, 7...27) and on ports 29,30,31,32.
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1 Gigabit and 10 Gigabit QSA is supported on all the 18 ports.
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Changing Mode 3 to any other mode or vice versa requires copy running-config startup-config command followed by reload command to take effect. However, moving between Modes 1 and 2 is dynamic and requires only copy running-config startup-config command.
Use the show running-config | grep portmode command to display the current operation mode.
Example:
switch(config-if-range)# show running-config | grep portmode
hardware profile portmode 4x100G+28x40G
With the Cisco Nexus C93180LC-EX switch, there are three breakout modes:
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40G to 4x10G breakout ports
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Enables the breakout of 40G ports into 4 X 10G ports.
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Use the interface breakout module 1 port x map 10g-4x command.
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100G to 4x25G breakout ports
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Enables the breakout of 100G ports into 4 X 25G ports.
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Use the interface breakout module 1 port x map 25g-4x command.
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100G to 2x50G breakout ports
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Enables the breakout of 100G ports into 2 X 50G ports.
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Use the interface breakout module 1 port x map 50g-2x command.
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