我原来是在校园网内用yum升级的，一直正常，学校用的是电信的网，最近回家改用网通的adsl发现无法更新，错误为
Loading "fastestmirror" plugin
Determining fastest mirrors
YumRepo Warning: not using ftp, http[s], or file for repos, skipping -
removing mirrorlist with no valid mirrors: //var/cache/yum/fedora/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: fedora
我添加了livna源，谁知道是怎么回事啊
