hi, i'm new to linux. right now i'm using centos 3.3. i want to upgrade to centos 3.4. i haven't used yum before. i have to go through a proxy to access the internet. so i thought it isn't able to access the proxy. after some searching on the net i could set the http proxy in the /etc/profile file. i used the following lines in the file(with the actual ip address and port ofcourse). set "http://my.domain.name:port/" export proxy_http="http://my.domain.name:port/" when i became the super user and tried the command 'yum install centos-yumcache', i got the messages attached below. [root at achala etc]# yum install centos-yumcache Gathering header information file(s) from server(s) Server: CentOS-3.3 - Addons retrygrab() failed for: http://mirror.centos.org/centos/3.3/addons/i386/headers/header.info Executing failover method failover: out of servers to try Error getting file http://mirror.centos.org/centos/3.3/addons/i386/headers/header.info [Errno 4] IOError: <urlopen error > there was some info on the centos site that when u first run yum a lot of headers would be downloaded. i think i don't have any downloaders with me. one more thing that i did with the yum.conf file was that i changed all the "centos-3"'s to "centos" in all the paths. can someone help me with this situation. thanks for any help. regards. chaitanya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com