Trunk between switches - help

Hi,

I have two switches crossed two floor as below

I'm going to create a trunk between two switches, port 1 on both switches. When I telnet to the 2924 and put below command in, the switch lost conenctivity immediately. I haven't configured the trunk port on 4505 yet, is this the problem cause ? If I configure the trunk port in 4506 then, will the trunk come up immediately. To configure a trunk port in 4506, should I use the same command ?

int f0/1 switch trunk encapsulation dot1q switch mode trunk speed 100 duplex full

As above scenario, configure a trunk port between swithes, I guess the trunk will be down to update the switching table, what's the expected downtime for this ?

Thanks,