rhn_check & yum hangs on Red Hat Enterprise Linux Server 5

Issue

• rhn_check & yum hangs on Red Hat Enterprise Linux Server 5

RHEL5 <--> Http Proxy <--> RHN

    #rhn_check -vvvvv 
    D: opening  db environment /var/lib/rpm/Packages joinenv 
    D: opening  db index       /var/lib/rpm/Packages rdonly mode=0x0 
    D: locked   db index       /var/lib/rpm/Packages 
    D: opening  db index       /var/lib/rpm/Providename rdonly mode=0x0 
    Could not retrieve action from <RetryServer for xmlrpc.rhn.redhat.com/XMLRPC>. 
    Possible networking problem? 
    D: closed   db index       /var/lib/rpm/Providename 
    D: closed   db index       /var/lib/rpm/Packages 
    D: closed   db environment /var/lib/rpm/Packages 
    D: May free Score board((nil))
    -----HANG