Switch: Trunk

Hello Experts,

Setting up a test environment on vlan and along with that some trunking.  Now, of course it takes two switches to set up trunking and if one port of the switch is set to trunk mode (fa0/24), do I need to set the port on the other switch also to trunk mode?  Tried and I'm getting an up and down status on the port.  Is that because I only need to  configure one of them?

As always, thank you for your time on this matter.
Who is Participating?
The_KirschiConnect With a Mentor Commented:
I am not sure if you need to setup the other side as a trunk, too. But if you do you should not get a problem. You could run into problems if you have multiple trunks on the switches. By default a trunk transports all vlan traffic and thus if you have multiple trunks you can create what is called loops. To prevent this the spanning-tree protocol is implemented in most switches. You could also prevent loops when you only allow specific vlans per trunk. On a cisco switch for example you could set the following in interface configuration mode:

conf t
int fa 0/24
switchport trunk allowed vlan 1


switchport trunk allowed vlan 1,2


switchport trunk allowed vlan 1-10

Does this help?
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