Redhat - LinuxConfig.org

Details: admin; Redhat; 07 April 2015

Instead of changing a hostname on your Redhat 7 server manually by editing /etc/hostname you may preferably use a dedicated command hostnamectl to do this job. By default when no other options are supplied the hostnamectl command will display basic information including static hostname:

[root@rhel7 ~]# hostnamectl 
   Static hostname: rhel7
         Icon name: computer
           Chassis: n/a
        Machine ID: 75387b56d72b44b380810499805ec28a
           Boot ID: 6ad251d0e12a10e3af1894eae5fe5cb6
    Virtualization: oracle
  Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
       CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:GA:server
            Kernel: Linux 3.10.0-123.el7.x86_64
      Architecture: x86_64

Details: admin; Redhat; 31 March 2015

The easiest way to create a Cisco VPN client connection on Redhat 7 Linux is to use vpnc client which is an opensource alternative to Cisco VPN client. Let's start by VPNC installation on RHEL7. The VPNC package is located within EPEL ( Extra Packages for Enterprise Linux 7 ) repository thus first enable EPEL repository:

# subscription-manager repos --enable=rhel-7-server-optional-rpms

Details: admin; Redhat; 17 March 2015

Previously we have talked about how to configure a default gateway on RHEL7 Linux. This time we will talk about how to add a static route on RHEL7 Linux.

Any network we are trying to reach is accessed via default gateway only if it is not implicitly overwritten by another static route definition. Let's have a look at a current routing table on our Redhat 7 Linux box:

root@rhel7 ~]# ip route show
default via 10.1.1.1 dev enp0s3  proto static  metric 1024 
10.0.0.0/8 dev enp0s3  proto kernel  scope link  src 10.1.1.110

Details: admin; Redhat; 10 January 2015

The way on how you can reset a forgotten root password on a Linux system have not changed for many years. Resetting a root password on RHEL7 Linux system have not change much except that now we deal with SElinux and the system is now using systemd instead of init. Nevertheless, those who have already did reset root password on the Linux system will be with the following steps familiar. Here is the procedure of what needs to be done in order to recover a forgotten root password on Redhat 7 Linux:

We need to edit GRUB2 boot menu and enter user single mode
Next, we need to remount / partition to allow read and write
Reset the actual root password
Set entire system for SElinux relabeling after first reboot
Reboot the system from a single mode

Now that we understand the procedure we can proceed with Redhat 7 password recovery.

Details: admin; Redhat; 02 January 2015

The firewall on Redhat 7 Linux system is enabled by default. Normally there should not be a need to disable firewall but it may be quite handy for testing purposes etc. On Redhat 7 Linux system the firewall run as firewalld daemon. Bellow command can be used to check the firewall status:

[root@rhel7 ~]# systemctl status firewalld
firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
   Active: active (running) since Thu 2014-09-04 19:18:47 EST; 3 months 28 days ago
 Main PID: 539 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─539 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Sep 04 19:18:45 rhel7 systemd[1]: Starting firewalld - dynamic firewall daemon...
Sep 04 19:18:47 rhel7 systemd[1]: Started firewalld - dynamic firewall daemon.

How to change a static hostname on RHEL7 linux with hostnamectl

Establishing Cisco VPN client connection on RHEL 7 using vpnc

How to add a new static route on RHEL7 Linux

Recover a forgotten root password on Redhat 7 Linux Selinux system

How to stop/start and disable/enable Firewall on Redhat 7 Linux system