[Errno 14] PYCURL ERROR 5 - "Couldn't resolve proxy 'http'"

Hi Everyone

Somebody could help me?
I have a problem when i try update the yum.

The error description is:

Complementos cargados:product-id, refresh-packagekit, search-disabled-repos, security, subscription-manager
Configurando el proceso de actualización
https://cdn.redhat.com/content/eus/rhel/server/6/6Server/x86_64/os/repodata/repomd.xml: [Errno 14] PYCURL ERROR 5 - "Couldn't resolve proxy 'http'"
Intentando con otro espejo.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: rhel-6-server-eus-rpms. Please verify its path and try again

I checked the up2date file and I configured the proxy and change "enableProxy" flag to 1.