There are 2 SW and 2 PCs. There is a trunk with VLAN 1 and 5 allowed. Question-is if you do "switchport trunk allowed vlan 2,3,4" on SW2, what happens. Ports towards PCs are in mode access VLAN 5
A. The connection is lost between PCs, because you will remove VLANs 1 and 5 from trunk with this command. You should use "switchport trunk allowed vlan" to add additional VLANs into trunk
You should use “switchport trunk allowed vlan ADD [vlan-id]” to add an additional vlan.