cl.releases.ubuntu.com
Index of /The following releases of Ubuntu are available:. Ubuntu 17.10 (Artful Aardvark). Ubuntu 16.04.4 LTS (Xenial Xerus). Ubuntu 14.04.5 LTS (Trusty Tahr). Ubuntu 12.04.5 LTS (Precise Pangolin). We are happy to provide hosting for the following projects via the cdimage server. While they are not commercially supported by Canonical, they receive full support from their communities. For old releases, see old-releases.ubuntu.com.
http://cl.releases.ubuntu.com/