On Tue, 2015-03-10 at 16:44 +0530, Ravi Roy wrote: > Hi Guys, > > My apologies for earlier mail without subject line. kindly ignore. > > i've CentOS 6.6 (Final) 64 bit version installed and I can not access the > online repositories to install/update (pls see eror below the error), I > tried to google this error I get a lot of links but nothing I could really > solving this issue. I've already disabled ipv6 and also defined proxy in > /etc/yum.conf. ... This is stating the obvious but it looks like your proxy definition in yum.conf does not work. I assume you have something like: proxy=http://<hostname>:<port> with a possible proxy_username=whoever and proxy_password=whatever if required in yum.conf Check these again, I find I often read what I thought I typed, not what I actually did. If this is correct tcpdump may give you some useful information on what is actually happening. Regards