Trunk only one VLAN to an attached switch.

Question

I have a netgear GSM7324 and a managed Cisco switch. I need to connect the Cisco switch to the netgear. The Cisco switch will only need to have vlan 3 on it. Do I still need to set up a trunk port to connect the Cisco and Netgear or would it just set it for switch port mode access and switch access vlan 3 ?

Answer 1

I'd create the vlan on both sides and use a tagged trunk port for this. It might sound overkill, but imagine the warm fuzzy feeling you'll get inside the day you need to add another VLAN to the switches.

Edit: It's easy on Cisco switches to limit which VLANS who can travel across the trunk port:

interface GigabitEthernet1/0/1
 description Trunkport to Netgear switch
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 1
 switchport trunk allowed vlan 3
 switchport mode trunk
 speed 1000
 duplex full
end

Answer 2

On Cisco equipment, VLAN 1 is always a member of any trunk - you cannot exclude it.

Either make sure you know the implications, or don't use VLAN 1.

Before someone thinks I misread his question - this means that ANY trunk with one defined VLAN will in actual fact contain two - the defined VLAN and VLAN 1.

Answer 3

If you just need one vlan the easiest and cleanest way is to set the port to access.

EDIT: Ok, so some questions:

• Do netgear support perVLAN spanning tree on its trunk ports?
• Do netgear support CDP or VTP?
• what kind of loop detection netgear uses?

If one just connect these two switches in their basement all is fine.

I saw huge problems connecting Huawei and Cisco switches in an enterprise network. However Huawei is not the cheapest SOHO gear.