On Fri, Apr 25, 2008 at 12:35:26PM +0530, JohnsonKoilraj wrote: > Hi > I am using centos 5. yum saying following error.. > > [root at zeus Desktop]# yum grouplist > Loading "installonlyn" plugin > Setting up Group Process > Setting up repositories > Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=5&arch=i386 > &repo=os error was > [Errno 14] HTTP Error 407: Proxy Authentication Required > Error: Cannot find a valid baseurl for repo: base > > my system is behind corporate filter. Is there any where to use yum. help me > out in this. in some forum it says we need NTLM to handle this... > > by > john > Sounds like you may need to do some proxy authentication. Do a man yum.conf and search for "proxy" and you should see a few parameters that might help you out. Throw these in /etc/yum.conf. Ray