you say you can ping the server, so it tells me the network interface is on, but it does not prove your default route is set correctly.
Also, to get to download mirrors (I suppose that's what I call a repository in Fedora), you need a working dns.
Here is a bit of homework for you.
use route command to know your different routers around you, and especially your default router.
try pinging that default router
#find what your dns server is set to:
ping that dns
#try using that dns:
#find your mirror server IP, can't help you there, that's Debian specific
#then try pinging it
With all of this, you should get an idea on where it's failing.