HP Cisco Catalyst Blade Switch 3020 Cisco Catalyst Blade Switch 3020 for HP Co - Page 527

Chapter 2 Cisco Catalyst Blade Switch 3020 for HP Cisco IOS Commands switchport mode To autonegotiate trunking, the interfaces must be in the same VLAN Trunking Protocol (VTP) domain. Trunk negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a point-to-point protocol. However, some internetworking devices might forward DTP frames improperly, which could cause misconfigurations. To avoid this, you should configure interfaces connected to devices that do not support DTP to not forward DTP frames, which turns off DTP. • If you do not intend to trunk across those links, use the switchport mode access interface configuration command to disable trunking. • To enable trunking to a device that does not support DTP, use the switchport mode trunk and switchport nonegotiate interface configuration commands to cause the interface to become a trunk but to not generate DTP frames. Access ports trunk ports are mutually exclusive. The IEEE 802.1x feature interacts with switchport modes in these ways: • If you try to enable IEEE 802.1x on a trunk port, an error message appears, and IEEE 802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled port to trunk, the port mode is not changed. • If you try to enable IEEE 802.1x on a port set to dynamic auto or dynamic desirable, an error message appears, and IEEE 802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled port to dynamic auto or dynamic desirable, the port mode is not changed. • If you try to enable IEEE 802.1x on a dynamic-access (VLAN Query Protocol [VQP]) port, an error message appears, and IEEE 802.1x is not enabled. If you try to change an IEEE 802.1x-enabled port to dynamic VLAN assignment, an error message appears, and the VLAN configuration is not changed. Examples This example shows how to configure a port for access mode: Switch(config)# interface gigabitethernet0/21 Switch(config-if)# switchport mode access This example shows how set the port to dynamic desirable mode: Switch(config)# interface gigabitethernet0/21 Switch(config-if)# switchport mode dynamic desirable This example shows how to configure a port for trunk mode: Switch(config)# interface gigabitethernet0/21 Switch(config-if)# switchport mode trunk You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC command and examining information in the Administrative Mode and Operational Mode rows. Related Commands Command show interfaces switchport switchport access switchport trunk Description Displays the administrative and operational status of a switching port, including port blocking and port protection settings. Configures a port as a static-access or dynamic-access port. Configures the trunk characteristics when an interface is in trunking mode. OL-8916-01 Cisco Catalyst Blade Switch for HP Command Reference 2-499