For every yum command it will return SSL certificate error
Loaded plugins: fastestmirror, rhnplugin, security
The SSL certificate failed verification.
My SSL cert if valid.
I checked rhel site for https://access.redhat.com/solutions/93313 but the problem is i cannot reinstall rhn-client-tools since yum is actually not working and for some other reasons i cannot boot it from DVD/image.
Before trying to reinstall, have you also checked your firewall settings and the time and date setting on your server ?
If the firewall is not the issue, I would suggest a simpler approach, just by going to RH’s site and downloading the appropriate rhn-client-tools RPM package, copying it to your server and installing it.
“What about the possible dependencies?” I foresee you asking…
Use a different server (or VM) with the same OS version that has access to the internet.
use yum with the download only plugin to only download all the needed dependencies (you must have the yum-plugin-downloadonly package installed beforehand) in a local directory like so: yum install --downloadonly --downloaddir=<directory> <package>
Copy the packages downloaded at step #2 to your affected machine and install them using the rpm utility as so: rpm -ivh /path/to/yum/download/dir/*