RHN にサーバーを登録しようとすると Temporary failure in name resolution エラーが表示される

Issue

• Red Hat Network (RHN) にシステムを登録できません。
• 以下のエラーが表示されます。

        Could not contact Red Hat Network (xmlrpc.rhn.redhat.com) 

• rhn_register コマンドは以下のエラーを表示します。

        An error has occurred:
        Temporary failure in name resolution
        See /var/log/up2date for more information

• 以下は /var/log/up2date に記録されるエラーです。

        [Mon Oct  3 09:09:05 2011] up2date A socket error occurred:(-3, 'Temporary failure in name resolution'), attempt #1
        [Mon Oct  3 09:09:11 2011] up2date A socket error occurred:(-3, 'Temporary failure in name resolution'), attempt #2
        [Mon Oct  3 09:09:16 2011] up2date A socket error occurred:(-3, 'Temporary failure in name resolution'), attempt #3
        [Mon Oct  3 09:09:21 2011] up2date A socket error occurred:(-3, 'Temporary failure in name resolution'), attempt #4
        [Mon Oct  3 09:09:26 2011] up2date A socket error occurred:(-3, 'Temporary failure in name resolution'), attempt #5
        [Mon Oct  3 09:09:26 2011] up2date Error communicating with server.The message was:
        Temporary failure in name resolution

• 以下は /var/log/RHSM/rhsm.log ファイルに記録されるエラーです。

[WARNING]  @certmgr.py:103 - Exception caught while running <subscription_manager.certlib.HealingLib object at 0x84e1410> update
[ERROR]  @certmgr.py:104 - (-3, 'Temporary failure in name resolution')