In this exercise, you will manually configure the system’s static host name, /etc/hosts file,
and DNS name resolver.

##OUTCOMES
You should be able to set a customized host name and configure name resolution settings.

##BEFORE YOU BEGIN
Log in as the student user on workstation using student as the password.

From workstation, run the lab net-hostnames start command. The command runs
a start script that determine if the host, servera, is reachable on the network.

[student@workstation ~]$ lab net-hostnames start

1. Use the ssh command to log in to servera as the student user. The systems are
   configured to use SSH keys for authentication, so a password is not required to log in to
   servera.

[student@workstation ~]$ ssh student@servera
...output omitted...
[student@servera ~]$

2. View the current host name settings.

      2.1. Display the current host name.

[student@servera ~]$ hostname
servera.lab.example.com

      2.2. Display the host name status.

[student@servera ~]$ hostnamectl status
Static hostname:    n/a
Transient hostname: servera.lab.example.com
Icon name:          computer-vm
Chassis:            vm
Machine ID:         73ab164e278e48be9bf80e80714a8cd5
Boot ID:            76b13a300c944ab49445af778cb8f749
Virtualization:     kvm
Operating System:   Red Hat Enterprise Linux 8.0 (Ootpa)
CPE OS Name:        cpe:/o:redhat:enterprise_linux:8.0:GA
Kernel:             Linux 4.18.0-80.el8.x86_64
Architecture:       x86-64

3. Set a static host name to match the current transient host name.

      3.1. Change the host name and host name onfiguration file.

[student@servera ~]$ sudo hostnamectl set-hostname
servera.lab.example.com
[sudo] password for student: student
[student@servera ~]$

      3.2. View the configuration file providing the host name at network start.

[student@servera ~]$ cat /etc/hostname
servera.lab.example.com

      3.3. Display the host name status.

4. Temporarily change the host name.

      4.1. Change the host name.

[student@servera ~]$ sudo hostname testname

      4.2. Display the current host name.

[student@servera ~]$ hostname
testname

      4.3. View the configuration file providing the host name at network start.

[student@servera ~]$ cat /etc/hostname
servera.lab.example.com

      4.4. Reboot the system.

[student@servera ~]$ sudo systemctl reboot
Connection to servera closed by remote host.
Connection to servera closed.
[student@workstation ~]$

      4.5. From workstation log in to servera as student user.

[student@workstation ~]$ ssh student@servera
...output omitted...
[student@servera ~]$

      4.6. Display the current host name.

[student@servera ~]$ hostname
servera.lab.example.com

5. Add a local nickname for the classroom server.

      5.1. Look up the IP address of the classroom.example.com.

[student@servera ~]$ host classroom.example.com
classroom.example.com has address 172.25.254.254

      5.2. Modify /etc/hosts so that the additional name of class can be used to access the IP address 172.25.254.254.

[student@servera ~]$ sudo vim /etc/hosts
[student@servera ~]$ cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.25.254.254 classroom.example.com classroom class
172.25.254.254 content.example.com content
...content omitted...

      5.3. Look up the IP address of class.

[student@servera ~]$ host class
Host class not found: 2(SERVFAIL)
[student@servera ~]$ getent hosts class
172.25.254.254 classroom.example.com class

      5.4. Ping class.

[student@servera ~]$ ping -c3 class
PING classroom.example.com (172.25.254.254) 56(84) bytes of data.
64 bytes from classroom.example.com (172.25.254.254): icmp_seq=1
ttl=64 time=0.397 ms
64 bytes from classroom.example.com (172.25.254.254): icmp_seq=2
ttl=64 time=0.447 ms
64 bytes from classroom.example.com (172.25.254.254): icmp_seq=3
ttl=64 time=0.470 ms
--- classroom.example.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.397/0.438/0.470/0.030 ms

      5.5. Exit from servera.

[student@servera ~]$ exit
logout
Connection to servera closed.
[student@workstation ~]$

##Finish

[student@workstation ~]$ lab net-hostnames finish

This concludes the guided exercise.