Cisco N7K-C7010 Configuration Guide - Page 85

Chapter 3 Configuring Layer 2 Interfaces Information About Access and Trunk Interfaces Send document comments to [email protected] Note The device supports only IEEE 802.1Q-type VLAN trunk encapsulation. Information About Access and Trunk Interfaces A Layer 2 port can be configured as an access or a trunk port as follows: • An access port can have only one VLAN configured on that port; it can carry traffic for only one VLAN. • A trunk port can have two or more VLANs configured on that port; it can carry traffic for several VLANs simultaneously. By default, all ports on the device are Layer 3 ports. You can make all ports Layer 2 ports using the setup script or by entering the system default switchport command. See the Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide, Release 5.x, for information on using the setup script. To configure the port as a Layer 2 port using the CLI, use the switchport command, All ports in one trunk must be in the same virtual device context (VDC). See the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 5.x, for information on VDCs. All ports in the same trunk must be in the same VDC, and trunk ports cannot carry VLANs from different VDCs. Figure 3-1 shows how you can use trunk ports in the network. The trunk port carries traffic for two or more VLANs. Figure 3-1 Trunk and Access Ports and VLAN Traffic VLAN 1 VLAN 2 VLAN 3 186703 Access Access Trunk Trunk Ethemet 1/1 Ethemet 1/2 Ethemet 2/1 Ethemet 2/2 Note See the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x, for information on VLANs. In order to correctly deliver the traffic on a trunk port with several VLANs, the device uses the IEEE 802.1Q encapsulation, or tagging, method (see the "IEEE 802.1Q Encapsulation" section on page 3-4 for more information). Note See the Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 5.x, for information on subinterfaces on Layer 3 interfaces. OL-23435-03 Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x 3-3