Red Hat Satellite 6 installation or upgrade fails with the error "invalid address (IPAddr::InvalidAddressError)"

Issue

• While installing or upgrading the Red Hat Satellite 6, it fails with the following error:

  Procedures::Installer::Upgrade: 
  /usr/share/ruby/ipaddr.rb:559:in `in6_addr': invalid address (IPAddr::InvalidAddressError)
      from /usr/share/ruby/ipaddr.rb:496:in `initialize'
      from /usr/share/katello-installer-base/checks/dns.rb:22:in `new'
      from /usr/share/katello-installer-base/checks/dns.rb:22:in `block in <main>'
      from /usr/share/katello-installer-base/checks/dns.rb:21:in `each'
      from /usr/share/katello-installer-base/checks/dns.rb:21:in `<main>'
  Your system does not meet configuration criteria
                                                                    [FAIL]
  Failed executing satellite-installer --upgrade, exit status 20