linux-redhat-repository-yum

We do the DVD mount process:

[root@localhost ~]# mount /dev/cdrom  /mnt

Now we copy the media index file to the system index:

[root@localhost ~]# cp /mnt/media.repo /etc/yum.repos.d/redhatDVD.repo
[root@localhost ~]# chmod 644 /etc/yum.repos.d/redhatDVD.repo

And edit adding the **bold lines:

[InstallMedia]
name=Red Hat Enterprise Linux 7.2
mediaid=1446216863.790260
metadata_expire=-1
**gpgcheck=1**
cost=500
**enabled=1
baseurl=file:///mnt/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release**

Clean the media/source info, doing:

 yum clean all

 subscription-manager clean

And tes if you can list the packages:
yum  --noplugins list

And test if you can install some package from the new media:

[root@localhost ~]# yum install firefox
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Resolving Dependencies
--> Running transaction check
---> Package firefox.x86_64 0:38.3.0-2.el7_1 will be installed
--> Processing Dependency: libvpx >= 1.3.0 for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: mozilla-filesystem for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: liberation-fonts-common for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: liberation-sans-fonts for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: libstartup-notification-1.so.0()(64bit) for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: libvpx.so.1()(64bit) for package: firefox-38.3.0-2.el7_1.x86_64
--> Processing Dependency: libXt.so.6()(64bit) for package: firefox-38.3.0-2.el7_1.x86_64
--> Running transaction check
---> Package libXt.x86_64 0:1.1.4-6.1.el7 will be installed
---> Package liberation-fonts-common.noarch 1:1.07.2-15.el7 will be installed
---> Package liberation-sans-fonts.noarch 1:1.07.2-15.el7 will be installed
---> Package libvpx.x86_64 0:1.3.0-5.el7_0 will be installed
---> Package mozilla-filesystem.x86_64 0:1.9-11.el7 will be installed
---> Package startup-notification.x86_64 0:0.12-8.el7 will be installed
--> Processing Dependency: libxcb-util.so.1()(64bit) for package: startup-notification-0.12-8.el7.x86_64
--> Running transaction check
---> Package xcb-util.x86_64 0:0.4.0-2.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

===============================================================================================================================================
 Package                                    Arch                      Version                            Repository                       Size
===============================================================================================================================================
Installing:
 firefox                                    x86_64                    38.3.0-2.el7_1                     InstallMedia                     72 M
Installing for dependencies:
 libXt                                      x86_64                    1.1.4-6.1.el7                      InstallMedia                    173 k
 liberation-fonts-common                    noarch                    1:1.07.2-15.el7                    InstallMedia                     27 k
 liberation-sans-fonts                      noarch                    1:1.07.2-15.el7                    InstallMedia                    279 k
 libvpx                                     x86_64                    1.3.0-5.el7_0                      InstallMedia                    498 k
 mozilla-filesystem                         x86_64                    1.9-11.el7                         InstallMedia                    5.4 k
 startup-notification                       x86_64                    0.12-8.el7                         InstallMedia                     39 k
 xcb-util                                   x86_64                    0.4.0-2.el7                        InstallMedia                     16 k

Transaction Summary
===============================================================================================================================================
Install  1 Package (+7 Dependent packages)

Total download size: 73 M
Installed size: 134 M
Is this ok [y/d/N]: