Table Of Contents

Overview

Information About Interfaces

Ethernet Interfaces

Access Ports

Trunk Ports

Private VLAN Hosts and Promiscuous Ports

Routed Ports

Management Interface

Port-Channel Interfaces

vPCs

Subinterfaces

VLAN Network Interfaces

Loopback Interfaces

Tunnel Interfaces

Fabric Extenders

Virtualization Interfaces

High Availability for Interfaces

Licensing Requirements for Interfaces

Overview

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This chapter provides an overview of the interface types supported by the Cisco NX-OS software.

This chapter includes the following sections:

•Information About Interfaces

•Virtualization Interfaces

•High Availability for Interfaces

•Licensing Requirements for Interfaces

Information 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.

Table 1-1 shows where to get further information on the parameters you can configure for an interface.

Table 1-1 Interface Parameters  

Feature	Parameters	Further Information
Basic parameters	description, duplex, error disable, flow control, MTU, beacon	Chapter 2 "Configuring Basic Interface Parameters" of this document
Layer 2	Layer 2 access and trunk port settings	Chapter 3 "Configuring Layer 2 Interfaces" of this document
	Layer 2 MAC, VLANs, private VLANs, Rapid PVST+, Multiple Spanning Tree, Spanning Tree Extensions	Layer 2 Switching Configuration Guide, Cisco DCNM for LAN, Release 5.x
	Port security	Security Configuration Guide, Cisco DCNM for LAN, Release 5.x
Layer 3	medium, IPv4 and IPv6 addresses	Chapter 4 "Configuring Layer 3 Interfaces" of this document
	bandwidth, delay, IP routing, VRFs	Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 5.x Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide, Release 5.x
Port Channels	channel group, LACP	Chapter 5 "Configuring Port Channels" of this document
vPCs	Virtual port channels	Chapter 6 "Configuring vPCs" of this document
Tunnels	GRE Tunneling	Chapter 7 "Configuring IP Tunnels" of this document
Security	Dot1X, NAC, EOU, port security	Security Configuration Guide, Cisco DCNM for LAN, Release 5.x
FCoE	Beginning with Cisco NX-OS Release 5.2(1), you can run Fibre Channel over Ethernet (FCoE) on the Cisco Nexus 7000 Series Switch	Cisco NX-OS FCoE Configuration Guide for Cisco Nexus 7000 and Cisco MDS 9500
Virtual Ethernet Interfaces	Logical interfaces that correspond to a switch interface connected to a virtual port	Chapter 8 "Configuring Virtual Ethernet Interfaces" of this document
Fabric Extenders	High-density, low-cost connectivity for server aggregation	Chapter 9 "Configuring Fabric Extenders" of this document
Port Profiles	A mechanism for simplifying the configuration of interfaces.	Chapter 10 "Configuring Port Profiles" of this document

This section includes the following topics:

•Ethernet Interfaces

•Management Interface

•Port-Channel Interfaces

•vPCs

•Subinterfaces

•VLAN Network Interfaces

•Loopback Interfaces

•Tunnel Interfaces

•Fabric Extenders

Ethernet Interfaces

Ethernet interfaces include access ports, trunk ports, private VLAN hosts and promiscuous ports, and routed ports.

This section includes the following topics:

•Access Ports

•Trunk Ports

•Private VLAN Hosts and Promiscuous Ports

•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 about access-port interfaces, see Chapter 3 "Configuring Layer 2 Interfaces."

Trunk Ports

A trunk port carries traffic for two or more VLANs. This type of port is a Layer 2 interface only. For more information about trunk-port interfaces, see Chapter 3 "Configuring Layer 2 Interfaces."

Private VLAN Hosts and Promiscuous Ports

Private VLANs (PVLANs) provide traffic separation and security at the Layer 2 level. A PVLAN is one or more pairs of a primary VLAN and a secondary VLAN, all with the same primary VLAN. The two types of secondary VLANs are called isolated and community VLANs.

In an isolated VLAN, PVLAN hosts communicate only with hosts in the primary VLAN. In a community VLAN, PVLAN hosts communicate only among themselves and with hosts in the primary VLAN but not with hosts in isolated VLANs or in other community VLANs. Community VLANs use promiscuous ports to communicate outside the PVLAN. Regardless of the combination of isolated and community secondary VLANs, all interfaces within the primary VLAN comprise one Layer 2 domain and require only one IP subnet.

You can configure a Layer 3 VLAN network interface, or switched virtual interface (SVI), on the PVLAN promiscuous port, which provides routing functionality to the primary PVLAN.

For more information on configuring PVLAN host and PVLAN promiscuous ports and all other PVLAN configurations, see the Layer 2 Switching Configuration Guide, Cisco DCNM for LAN, Release 5.x.

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 and does not support Layer 2 protocols, such as Spanning Tree Protocol (STP). 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 . 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 8 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 Chapter 5 "Configuring Port Channels."

vPCs

Virtual port channels (vPCs) allow links that are physically connected to two different Cisco Nexus 7000 series devices to appear as a single port channel by a third device. The third device can be a switch, server, or any other networking device. You can configure a total of 768 vPCs on each device. vPCs provide Layer 2 multipathing. For more information about vPCs, see Chapter 6 "Configuring vPCs."

Subinterfaces

You can create virtual subinterfaces on a parent interface configured as a Layer 3 interface. A parent interface can be a physical port or a port channel. 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. For more information on subinterfaces, see the "Subinterfaces" section.

VLAN Network Interfaces

A VLAN network interface is a virtual routed interface that connects a VLAN on the device to the Layer 3 router engine on the same device. You can route across VLAN network interfaces to provide Layer 3 inter-VLAN routing. For more information on VLAN network interfaces, see the "VLAN Interfaces" section.

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 on subinterfaces, see the "Loopback Interfaces" section.

Tunnel Interfaces

Tunneling allows you to encapsulate arbitrary packets inside a transport protocol. This feature is implemented as a virtual interface to provide a simple interface for configuration. The tunnel interface provides the services necessary to implement any standard point-to-point encapsulation scheme. You can configure a separate tunnel for each link. For more information, see Chapter 7 "Configuring IP Tunnels."

Fabric Extenders

Beginning with DCNM Release 4.2(1), the Cisco Nexus 2000 Series Fabric Extender works in conjunction with Cisco NX-OS devices to provide high-density, low-cost connectivity for server aggregation. Scaling across 1-Gigabit Ethernet, 10-Gigabit Ethernet, unified fabric, rack, and blade server environments, the Fabric Extender is designed to simplify data center architecture and operations.

The Fabric Extender integrates with its parent switch, the Cisco NX-OS switch, to allow automatic provisioning and configuration taken from the settings on the parent switch. This integration allows large numbers of servers and hosts to be supported using the same feature set as the parent switch, including security and Quality of Service (QoS) configuration parameters, with a single management domain. The Fabric Extender and its parent switch enable a large multipath, loop-free, active-active data center topology without the use of Spanning Tree Protocol (STP).

The Cisco Nexus 2148T Fabric Extender forwards all traffic to its parent Cisco NX-OS switch over 10-Gigabit Ethernet fabric uplinks, allowing all traffic to be inspected by policies established on the Cisco NX-OS switch.

Virtualization Interfaces

You can create multiple virtual device contexts (VDCs). Each VDC is an independent logical device to which you can allocate interfaces. Once an interface is allocated to a VDC, you can only configure that interface if you are in the correct VDC. For more information on VDCs, see the Virtual Device Context Configuration Guide, Cisco DCNM for LAN, Release 5.x.

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 after the switchover.

Licensing Requirements for Interfaces

IP tunnels and vPCs require the Enterprise Services license. You must install this license on every system that enables IP tunnels. All other interfaces do not require a license.