We have 5017R-MF, on website:
http://www.supermicro.com/products/system/1u/5017/sys-5017r-mf.cfm
it says:
USB • 9 USB 2.0 ports total
(2 rear + 6 via headers + 1 Type A)
I was wondering if those 6 ports can be used on front side with some kind of front USB access extension?
No, this system does not have option for front USB access, you need to use add on USB card for extra USB, or use 3rd party USB extension to rear side expansion slot.