The most convenient way to download an installation DVD for Fedora 11 to your hard drive is using bittorrent clients for Linux.
First, install KTorrent if you do not find it in Applications -> Internet:
sudo yum -y install ktorrent
Launch KTorrent and tune it according to your network requirements. Then go to //torrent.fedoraproject.org/ in your favourite browsers, click the desired distribution link and open it in KTorrent. The download should begin like the below: