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What’s the difference between “switchport mode access” and “switchport access vlan xx”?
First of all, both commands are required to set the switch to an access port.
switch(config-if)# switchport mode access
This above command disables DTP – Dynamic Trunking Protocol on the specified interface and basically turns off trunk negotiation. This command is important for any access port setting because without this command the port can be easily setup as a trunk interface.
switch(config-if)# switchport access vlan 10
This command sets the port to access vlan 10. Without the switchport mode access command, if the neighbouring port is a trunk port, the port will be configured as a trunk.
To confirm whether trunking has been disabled on an interface use the following command:
show interfaces switchport
Name: Fa0/2 Switchport: Enabled Administrative Mode: static access Operational Mode: static access Administrative Trunking Encapsulation: negotiate Operational Trunking Encapsulation: native Negotiation of Trunking: Off Access Mode VLAN: 10 (INTERNET) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: enabled Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk Native VLAN tagging: enabled Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none
Notice that the “negotiation of trunking:” is set to off.
You can also use the following command to confirm whether the port is setup as a trunk.
show interfaces trunk
What’s the best command to use for a port that will be connected to a host?
If you want to setup an access port for hosts, I would recommend using this command to save some typing:
switch(config-if)# switchport host
This command will automatically setup the port with a bunch of useful commands specifically designed for end host devices.
switchport mode will be set to access spanning-tree portfast will be enabled channel group will be disabled
