Q:

what are public yum respositories for red hat linux

I have a red hat linux machine and when I try to install any software it says my system is not registered how should I install
[root@JMNGD1BLT230V01 yum.repos.d]# yum install gettext-devel openssl-devel perl-CPAN perl-devel zlib-devel
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
No package gettext-devel available.
No package openssl-devel available.
No package perl-CPAN available.
No package perl-devel available.
Nothing to do

following are my repolist
[root@JMNGD1BLT230V01 yum.repos.d]# yum repolist
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
repo id             repo name                                             status
rsyslog-v7-stable   Adiscon Rsyslog v7-stable for CentOS-6Server-x86_64     896
rsyslog-v8-stable   Adiscon Rsyslog v8-stable for CentOS-6Server-x86_64   1,071
repolist: 1,967

A:

Red Hat requires a subscription to make use of their repositories, meaning you need to join their developer program or pay for a subscription.
If you don't actually need Red Hat specifically (or a service contract), you might instead try CentOS. It's pretty much the same thing as RHEL except with slightly slower updates, a few different default configurations, no Red Hat branding, and no service subscription (meaning it's free).
If you have a subscription already, follow the steps outlined on Red Hat's knowledgebase: https://access.redhat.com/solutions/253273

A:

You can install CentOS repos, if you don't have subscription to Red Hat.
See this link on migrating from RedHat packages to CentOS packages.
https://wiki.centos.org/HowTos/MigrationGuide
From the link:
Migrate an existing system from RHEL6 or SL6 to CentOS 6
To migrate from RHEL6 to CentOS 6 fetch the latest versions of the following packages for your architecture and put them in a temporary directory. Rather than fetching packages with wget, as shown below, the CentOS-6 installation media can be mounted and packages installed from it. For CentOS 6.2 x86_64
mkdir TMP
yum remove rhnlib abrt-plugin-bugzilla redhat-release-notes*
rpm -e --nodeps redhat-release redhat-indexhtml
cd TMP
wget http://mirror.centos.org/centos/6/os/x86_64/Packages/centos-release-6-2.el6.centos.7.x86_64.rpm
wget http://mirror.centos.org/centos/6/os/x86_64/Packages/centos-indexhtml-6-1.el6.centos.noarch.rpm
wget http://mirror.centos.org/centos/6/os/x86_64/Packages/yum-3.2.29-22.el6.centos.noarch.rpm
wget http://mirror.centos.org/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-10.el6.noarch.rpm
rpm -Uvh *.rpm
cd ..
rm -rf TMP
yum clean all
yum upgrade

For CentOS 6.2 i386 only the wget lines change:
wget http://mirror.centos.org/centos/6/os/i386/Packages/centos-release-6-2.el6.centos.7.i686.rpm
wget http://mirror.centos.org/centos/6/os/i386/Packages/centos-indexhtml-6-1.el6.centos.noarch.rpm
wget http://mirror.centos.org/centos/6/os/i386/Packages/yum-3.2.29-22.el6.centos.noarch.rpm
wget http://mirror.centos.org/centos/6/os/i386/Packages/yum-plugin-fastestmirror-1.1.30-10.el6.noarch.rpm

