The others were correct with the "interface range"
command, the key thing to remember is the space
between the first interface number and the "-".
If you don't put that there, the command interpreter
will not read the command properly.
switch#interface range fa0/1 -23 <enter> !(3550)
switch#interface range fa1/0/1 -23 <enter> !(65xx/3750)
switch#interface range gi1/0/1 -23 <enter> !(65xx/3750g)
switch#no shut <enter>
switch#exit or <ctrl-Z> <enter>
on the newer versions of IOS, if you are cutting/pasting
and you have a commands for a single interface or other
global comman, you should exit back one level out of
the interface level. If you don't, you'll get an error,
that may or may not allow the rest of the configurations
to be entered into the config.