Red Hat Network (abbreviated to RHN) is a family of systems-management services operated by Red Hat. RHN makes updates, patches, and bug fixes of packages included within Red Hat Linux and Red Hat Enterprise Linux available to subscribers. Other available features include the deployment of custom content to, and the provisioning, configuration, reporting, monitoring of client systems.
In the basic subscription model the information about a managed host is stored on Red Hat's servers, and updates get downloaded directly from those servers as well. For an organization that manages multiple machines this is inefficient bandwidth-wise. Red Hat offers a proxy server (Red Hat Network Proxy) that once installed at a site allows machines to securely download updates locally. Advanced lifecycle management; provisioning features, like bare metal PXE boot provisioning; and monitoring features (e.g. centralized CPU and disk usage) cannot be done over the Internet to the hosted RHN servers. These features require a RHN Satellite Server running locally. As of December 2009[update] the RHN Proxy Server costs $2,500 annually, and the RHN Satellite Server costs $13,500 annually, which includes the license for the embedded Oracle Database.
Red Hat Enterprise Linux 5 is now supported as a base operating system, introducing Oracle 10g support.
September 2, 2009
RHN Satellite 5.3 released
introducing significant upgrade of Multiple Organizations feature, automated system installation via the cobbler, Inter-Satellite Sync, supporting installation as VMWare guest, command line installation of RHN Proxy, SELinux support. 
October 27, 2010
RHN Satellite 5.4 released
supporting Red Hat Enterprise Linux 6 clients, introducing spacewalk-repo-sync, Duplicate Profile feature, Support for Oracle 11g, package installation date, symbolic links in configuration management and SELinux support for configuration management. 
June 16, 2011
RHN Satellite 5.4.1 released
Red Hat Enterprise Linux 6 is now supported as a base operating system. Internationalized domain names support added. 
Enhanced subscription and system reporting, Client system service analysis, Inter-Satellite Sync (ISS) content management and trust refinement, Red Hat Satellite server hot-backups, Automated provisioning in PXE-less environments, Red Hat Satellite server scalability, Choice of external, DBA-managed database