RHCSA Rapid Track

Instructions

1. On the workstation machine, use the ssh command to log in to the servera machine as the student user.

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

2. Locate network interface names with the ip link command.

   Important

   Network interface names are determined by their bus type and the detection order of devices during boot. Your network interface names might vary according to the course platform and hardware in use.

   Locate the network interface name that is associated with the Ethernet address on your system. Record or remember this name, and use it to replace the en_X_ placeholder in subsequent commands. The active connection is called System eth0, and the configuration is in the /etc/NetworkManager/system-connections/"System eth0.nmconnection" file.

   [student@servera ~]$ ip link
   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
       link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
       link/ether 52:54:00:00:fa:0a brd ff:ff:ff:ff:ff:ff
       altname enp0s3
       altname ens3
   3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8942 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
       link/ether fa:16:3e:15:d4:0d brd ff:ff:ff:ff:ff:ff
       altname enp0s4
       altname ens4
   [student@servera ~]$ nmcli con show --active
   NAME         UUID                                  TYPE      DEVICE
   System eth0  5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03  ethernet  eth0
   System eth1  9c92fad9-6ecb-3e6c-eb4d-8a47c6f50c04  ethernet  eth1
   lo           0e77d074-dd20-465e-87f5-e3974e6f42ab  loopback  lo
   [student@servera ~]$ ls /etc/NetworkManager/system-connections/
   'System eth0.nmconnection'

3. On the servera machine, switch to the root user, and then edit the /etc/NetworkManager/system-connections/"System eth0.nmconnection" file to add the 10.0.1.1/24 address.

   1. Use the sudo -i command to switch to the root user.

      [student@servera ~]$ sudo -i
      [sudo] password for student: student
      [root@servera ~]#

   2. Edit the /etc/NetworkManager/system-connections/"System eth0.nmconnection" configuration file. Add the 10.0.1.1/24 address as the second address below the first address in the file.

      ...output omitted...
      [ipv4]
      address1=172.25.250.10/24,172.25.250.254
      address2=10.0.1.1/24
      ...output omitted...

4. Activate the new network address with the nmcli command.

   1. Reload the configuration changes for NetworkManager to read the changes.

      [root@servera ~]# nmcli con reload

   2. Activate the connection with the changes.

      [root@servera ~]# nmcli con up "System eth0"
      Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/4)

5. Verify that the new IP address is assigned successfully.

   [root@servera ~]# ip -br addr show eth0
   eth0             UP             172.25.250.10/24 10.0.1.1/24 fe80::5054:ff:fe00:fa0a/64

6. Return to the workstation machine as the student user.

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

7. On the serverb machine, edit the /etc/NetworkManager/system-connections/"System eth0.nmconnection" file to add an address of 10.0.1.2/24 and load the new configuration.

   1. Log in to the serverb machine as the student user and switch to the root user.

      [student@workstation ~]$ ssh student@serverb
      ...output omitted...
      [student@serverb ~]$ sudo -i
      [sudo] password for student: student
      [root@serverb ~]#

   2. Edit the /etc/NetworkManager/system-connections/"System eth0.nmconnection" configuration file. Add the 10.0.1.2/24 address as the second address below the first address in the file.

      ...output omitted...
      [ipv4]
      address1=172.25.250.11/24,172.25.250.254
      address2=10.0.1.2/24
      ...output omitted...

   3. Reload the configuration changes for NetworkManager to read the changes.

      [root@serverb ~]# nmcli con reload

   4. Activate the connection with the changes.

      [root@serverb ~]# nmcli con up "System eth0"
      Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/4)

   5. Verify that the new IP address is assigned successfully.

      [root@serverb ~]# ip -br addr show eth0
      eth0             UP             172.25.250.11/24 10.0.1.2/24 fe80::5054:ff:fe00:fa0b/64

8. Test connectivity between the servera and serverb machines by using the new network addresses.

   1. From the serverb machine, ping the new address of the servera machine.

      [root@serverb ~]# ping -c3 10.0.1.1
      PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
      64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=1.23 ms
      64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=0.372 ms
      64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.440 ms
      
      --- 10.0.1.1 ping statistics ---
      3 packets transmitted, 3 received, 0% packet loss, time 2040ms
      rtt min/avg/max/mdev = 0.372/0.679/1.225/0.387 ms

   2. Return to the workstation machine as the student user.

      [root@serverb ~]# exit
      logout
      [student@serverb ~]$ exit
      logout
      Connection to serverb closed.
      [student@workstation ~]$

   3. Access the servera machine as the student user to ping the new address of the serverb machine.

      [student@workstation ~]$ ssh student@servera ping -c3 10.0.1.2
      PING 10.0.1.2 (10.0.1.2) 56(84) bytes of data.
      64 bytes from 10.0.1.2: icmp_seq=1 ttl=64 time=0.726 ms
      64 bytes from 10.0.1.2: icmp_seq=2 ttl=64 time=0.349 ms
      64 bytes from 10.0.1.2: icmp_seq=3 ttl=64 time=0.342 ms
      
      --- 10.0.1.2 ping statistics ---
      3 packets transmitted, 3 received, 0% packet loss, time 2087ms
      rtt min/avg/max/mdev = 0.342/0.472/0.726/0.179 ms