Red Hat Enterprise Linux で yum コマンドを実行すると [Errno 14] PYCURL ERROR 7 - "couldn't connect to host " が発生する

Issue

• # yum update を実行すると以下のエラーメッセージが発生します。

# yum update
Loaded plugins: product-id, rhnplugin, security
redhat-rhn-satellite-5.5-server-x86_64-6                                                                                         | 1.6 kB     00:00     
https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/cf-tools/1/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 22 - "The requested URL returned error:403"
Trying other mirror.
https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/rhev-agent/3/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 22 - "The requested URL returned error:403"
Trying other mirror.
https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 22 - "The requested URL returned error:403"
Trying other mirror.
Error: failed to retrieve repodata/e847e0e8ad4903bd2acbbeea4eb487dbd3af3061a40b5a7f074f9e60709d49b7-updateinfo.xml.gz from redhat-rhn-satellite-5.5-server-x86_64-6
error was [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"

• yum が失敗し以下のエラーが発生します。

Error: failed to retrieve repodata/c964d1bced53b5fb02369d8429e2d2cd5a8699c6bab094b473f9e830afaa75a7-primary.xml.gz from rhel-x86_64-server-6
error was [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"

• Red Hat Subscription Manager を使用してシステムを登録し、yum update や yum list などの yum コマンドを実行すると失敗し、以下のようなエラーが発生します。

ftp://ftp.redhat.com/pub/redhat/linux/beta/6Server/en/os/SRPMS/repodata/repomd.xml:[Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
Error:Cannot retrieve repository metadata (repomd.xml) for repository: rhel-source-beta.Please verify its path and try again