Perform the next steps to add RHEL installation DVD as repository.
Step 1: Create mount point and mount the DVD
$ mkdir /mnt/rhel-dvd && mount -t iso9660 -o ro /dev/cdrom /mnt/rhel-dvd
Step 2: Create RHEL repo list and call it ‘rhel-dvd.repo’
$ touch /etc/yum.repos.d/rhel-dvd.repo
Step 3: Add the following config to ‘rhel-dvd.repo’
[rhel-dvd] name=Red Hat Enterprise Linux $releasever - $basearch - DVD baseurl=file:///mnt/rhel-dvd/ enabled=1 gpgcheck=0
Step 4: Clean your cache
$ yum clean all
Now you can install the new software from the DVD using ‘yum install’ command.
At least with RHEL 8.5 baseurl is:
baseurl=file:///mnt/rhel-dvd/BaseOS