I recently installed Fedora Core 8, and since install the clock has been 4 hours fast and an attempt to update the time yields an error stating the site cannot be reached. Add/Remove Software locks up, and eventually gives an error stating the repositories cannot be accessed because of the network connection. These things tell me Fedora itself isn't connecting for some reason.
However, I can get on Konqueror (I chose KDE from the Live CD) and browse this and other webpages with no problems whatsoever. I am connected through a router to a DSL modem. I can ping successfully. I've tried this:
[Zac@localhost ~]$ su -
[root@localhost ~]# yum install yum-fastestmirror
Could not retrieve mirrorlist http://mirrors.fedoraproject.org/mir...de&arch=x86_64
[Errno 4] IOError: <urlopen error (101, 'Network is unreachable')>
Error: Cannot retrieve repository metadata (repomd.xml) for repository: development. Please verify its path and try again