I am having trouble configuring trunking on these switches. I am unsure how to configure different VLANs on different switches, each connected to one another. I tried to configure the 802.1Q trunk on these switches using the switchport encapsulation command. However, every time I issue this command, an error message occurs. I tried configuring the interface with the switchport mode trunk command. However, every time I issue the switchport allowed vlan command and then the VLAN numbers I want to enable, which are 1-3, I get an error message. Could you please provide an explanation as clearly as possible.
Switch1-vlan 1 is called Research and management.
Switch2- vlan2 is called Sales and Marketing
Switch3- vlan 3 is the server vlan
Best Answer
The allowed vlan command is not correct. Try using:
As mentioned you'll want to ensure that all three switches have the vlans created and that all three are trunked on all links.
The above command will allow you to verify the trunking protocol and vlans in the trunk. as mentioned, some switches only support one protocol, and do not allow the encapsulation to be configured.
Also, it's a best practice to not use vlan 1 for anything.