yum install cannot find nagios server package 3.2.3-2.el6

In http://incubator.apache.org/ambari/1.2.2/installing-hadoop-using-ambari/content/ambari-chap1-5-1.html

When I try to install nagios 3.2.3-2.el6 I get the following error

yum install nagios 3.2.3-2.el6
Loaded plugins: amazon-id, product-id, rhui-lb, security, subscription-manager
Updating certificate-based repositories.
Unable to read consumer identity
Setting up Install Process
No package nagios available.
No package 3.2.3-2.el6 available.
Error: Nothing to do