1.RHN vs NRH  1. About RHN 　RHN is short for RedHatNetwork, and system is offered by RedHat software company for update files download.   There are the following three kinds of using RHN to be registered.   - DEMO         Free user   - BASIC        Annual $60 per one system   - ENTERPRISE   Annual $96 per one system RedHat Network Feature DEMO BASIC ENTERPRISE Prise Survey 60/Sys/Year 96/Sys/Year Errata Notification, Single System Be the first to know about Red Hat's patches. Subscribe to email errata notification through Red Hat Network. V V V Errata Updates, Single System Immediately bring individual systems up-to-date with the click of a button. V V V Search Packages Search through the full repository of RPMs available to Red Hat Network users. V V V Search Errata Search through the collection of all errata ever released through Red Hat Network. V V V Easy ISOs For customers who have purchased subscriptions to Red Hat Network, ISO images of Red Hat Linux are available for immediate download. Beat the rush to the FTP servers by downloading directly from Red Hat Network. 　 V V Priority Access during periods of high load When Red Hat releases a large errata, users with Priority Access can be guaranteed that they will be able to access the updated packages immediately. 　 V V Auto Update This optional feature allows you to set RHN to update your system automatically. This means no more manual updates, and ensures that you always have the latest errata as soon as possible. 　 V V RHN Support Access All paying customers of Red Hat Network receive web based support for their RHN questions. PLEASE NOTE that this is support for RHN only (see the Service Level Agreement). If you are interested in support for Red Hat Linux, you can purchase Support on Demand, or go to the Red Hat Support page. 　 V V Errata Notification, Multiple Systems Subscriptions for multiple systems means errata notification for errata to all of those systems. 　 V V Errata Updates, Multiple Systems Get quick updates for multiple systems with an easy button click for each system. 　 V V Package Profile Comparison Compare the package set on a system with the package sets of similar systems with one click. 　 　　 V Search Systems Search through systems based on a number of criteria: packages, networking information, even hardware asset tags. 　 　　　 V System Grouping Web servers, database servers, workstations and other workload-focused systems may be grouped so that each set can be administered in common ways. 　 　 V Multiple Administrators Administrators may be given rights to particular system groups, easing the burden of system management over very large organizations. 　 　 V System Set Manager You may now apply actions to sets of systems instead of single systems. Work with members of a predefined system group, or work with an ad-hoc collection of systems. Install a single package to each, subscribe them all to a new channel, or apply all errata to them with a single action. 　 　 V Massive Scalability Figuring out a list of outdated packages for a thousand systems would take days for a dedicated sysadmin. Red Hat Network Enterprise Service can do it for you in seconds. 　 　 V  2. About NRH   NRH is short for Not RedHat,the RHN server system which does not use RHN.   This system is developed by Mr. Alex.   Support version is as follows   Server system   RedHat7.3 and more   Client system   up2date V2.8 and more   The version which can be Update files distributed.   - RedHat7.1   - RedHat7.2   - RedHat7.3   - RedHat8.0   - RedHat9   - RedHatAS2.1 Let's build order for building of NRH-up2date from the following page.