A question on port fast and trunk

[manoj-j]

As per cisco recommendations we can't use port fast on trunk or uplink ports. But when i open VM and login into WLC and try to configure the ethernet port I have observed we have a drop down in port fast tab including trunk. How can we choose trunk in port fast. Can any one solve the question. 

[marce1000]

 -Why do you need to open VM first to connect to the WLC ?

 M.

[Rich R]

What model of WLC?
What version of software?
Provide a screenshot of the screen you are referring to?

Portfast is a spanning tree setting normally configured on switch ports not WLCs!
And there are situations where portfast can be used on trunk ports - there's even a trunk specific version of the command:
spanning-tree portfast edge trunk
It comes with caveats and warnings, of course, because there are risks involved, so you should only use it when 100% sure that it is safe to do so and will not create a loop.

[Scott Fella]

PortFast is a feature configured on the switch side for any access port or trunk port that is directly connected to a device, such as a Cisco WLC. It is important to note that PortFast should be enabled on the switch port that connects to the WLC. No configuration is required on the WLC itself or any other connecting device. You should also provide as much information when asking a question, this info help us understand what the issue might be.