YUM MY!!!

I had a hard time setting up my YUM (FC4) because i was BEHIND a FIREWALL with AUTHENTICATION :(

Finally, after some research, I had to edit /etc/yum.conf

and added this line

[main]
proxy=http://username:password@ip_address:port
cachedir=/var/cache/yum
....
...
...
didn't work for me, so I added the environment variable "HTTP_PROXY"
e.g
HTTP_PROXY=http://username:password@ip_address:port and
export HTTP_PROXY