Red Hat System Administration I

View the current host name settings.

1. Display the current host name.

   [student@serverX ~]$ hostname
   serverX.example.com
   

2. Display the host name status.

   [student@serverX ~]$ hostnamectl status
      Static hostname: n/a
   Transient hostname: serverX.example.com
            Icon name: computer
              Chassis: n/a
           Machine ID: 9f6fb63045a845d79e5e870b914c61c9
              Boot ID: d4ec3a2e8d3c48749aa82738c0ea946a
     Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
          CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:GA:server
               Kernel: Linux 3.10.0-97.el7.x86_64
         Architecture: x86_64
   

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

1. Change the host name and host name configuration file. Replace the X with your station number and match the output of the previous step.

   [student@serverX ~]$ sudo hostnamectl set-hostname serverX.example.com
   

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

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

3. Display the host name status.

   [student@serverX ~]$ hostnamectl status
      Static hostname: serverX.example.com
            Icon name: computer
              Chassis: n/a
           Machine ID: 9f6fb63045a845d79e5e870b914c61c9
              Boot ID: d4ec3a2e8d3c48749aa82738c0ea946a
     Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
          CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:GA:server
               Kernel: Linux 3.10.0-97.el7.x86_64
         Architecture: x86_64
   

Temporarily change the host name.

1. Change the host name.

   [student@serverX ~]$ sudo hostname testname
   

2. Display the current host name.

   [student@serverX ~]$ hostname
   testname
   

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

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

4. Reboot the system.

   [student@serverX ~]$ reboot
   

5. Display the current host name.

   [student@serverX ~]$ hostname
   serverX.example.com
   

Add a local nickname for the classroom server.

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

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

2. Modify /etc/hosts so that the name class has the IP address 172.25.254.254 and can be used to communicate with classroom.example.com.

   [student@serverX ~]$ sudo vim /etc/hosts
   [student@serverX ~]$ 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 class
   172.25.254.254 content.example.com
   

3. Look up the IP address of the class.

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

4. Ping class.

   [student@serverX ~]$ 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