In RHEL 5, the package manager is yum (packaging format: RPM). Because the subscription is expired, running yum install <package> will fail with SSL or connection errors.
Released in July 2011, represents a significant milestone in the lifecycle of the RHEL 5 series. As a mature update to the Red Hat Enterprise Linux 5 operating system, version 5.7 focused on refining stability, enhancing hardware support, and streamlining virtualization capabilities for enterprise environments. Core Focus of RHEL 5.7 rhel 5.7