Practices for Lesson 15: Overview Practices Overview
Practice 15-2: Using NetworkManager with the GNOME GUI Overview
In this practice, you:
• Ensure that the NetworkManager software package is installed
• Use the NetworkManager GUI to view network status and to disable and enable a network interface
• Use NetworkManager’s Network Settings window to disable and enable a network connection
• Use the Network Settings window to configure a network connection
• Use the Network Settings window to add a connection profile
• Use the NetworkManager GUI to select a different connection profile
• View the network interface configuration file for the new connection profile Assumptions
• You are connected to host03 VM by using vncviewer.
• You are the root user on host03 VM.
Tasks
1. Install and start NetworkManager if necessary.
• NetworkManager is installed and running if you see this computer screen icon on the GNOME panel as follows:
a. Use the rpm command to verify that the NetworkManager package is installed.
# rpm –qa | grep –i networkmanager NetworkManager-libreswan-...
NetworkManager-config-server--...
NetworkManager-glib-...
NetworkManager-...
• In this example, NetworkManager is installed.
b. If NetworkManager is not installed, use the yum command to install the package.
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• In this example, NetworkManager is running.
d. If NetworkManager is not running, use the systemctl command to start it.
# systemctl start NetworkManager
2. Use NetworkManager to view network status and disable and enable a network interface.
a. Select the computer screen icon to display the following:
• In this example, there are two Ethernet interfaces.
• Both network interfaces are ON.
b. Select the Ethernet (eth1) entry to toggle the ON/OFF switch to OFF.
• Select the computer screen icon again to show that Ethernet (eth1) is OFF.
c. From a command window, use the ip addr command to display the status of the interfaces.
# ip addr ...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 00:16:3e:00:02:03 brd ff:ff:ff:ff:ff:ff
• Note that the eth1 interface does not have IP addresses.
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d. Select the computer screen icon and then select the Ethernet (eth1) entry to toggle the ON/OFF switch to ON.
• Select the computer screen icon again to show that Ethernet (eth1) is ON.
e. From a command window, use the ip addr command to display the status of the interfaces.
# ip addr ...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 00:16:3e:00:02:03 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.103/24 brd 192.168.1.255 scope global eth1 inet6 ...
...
• Note that the eth1 interface now has IP addresses.
3. Use the Network Settings window to disable and enable a network connection.
a. Select the computer screen icon to display the following drop-down menu:
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b. Select Network Settings to display the following screen:
c. Select the Ethernet (eth1) entry on the left and then toggle the ON/OFF switch to OFF.
• The window displays as shown.
d. From a command window, use the ip addr command to display the status of the interfaces.
# ip addr ...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 00:16:3e:00:02:03 brd ff:ff:ff:ff:ff:ff
• Note that the eth1 interface does not have IP addresses.
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e. Select the Ethernet (eth1) entry on the left and then toggle the ON/OFF switch to ON.
• The window displays as shown.
f. From a command window, use the ip addr command to display the status of the interfaces.
# ip addr ...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 00:16:3e:00:02:03 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.103/24 brd 192.168.1.255 scope global eth1 inet6 ...
...
• Note that the eth1 interface now has IP addresses.
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4. Use the Network Settings window to configure a network connection.
a. Select the Ethernet (eth1) entry on the left and then select the gear icon in the lower right corner of the window as shown:
• The window displays as shown:
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b. Select the Security entry on the left.
• The window displays as shown:
c. Toggle the ON/OFF switch to ON to enable 802.1x Security.
d. Select each Authentication option and view the configuration setting options:
• MD5 (message-digest algorithm)
• TLS (Transport Layer Security)
• FAST (Flexible Authentication via Secure Tunneling)
• Tunneled TLS
• PEAP (Protected Extensible Authentication Protocol) e. Toggle the ON/OFF switch to OFF to disable 802.1x Security.
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f. Select the Identity entry on the left.
• The window displays as shown:
• Note the available settings on this window.
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g. Select the IPv4 entry on the left.
• The window displays as shown:
• Note the available settings on this window.
• Scroll down to view all settings.
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h. Select the IPv6 entry on the left.
• The window displays as shown:
• Note the available settings on this window.
• Scroll down to view all settings.
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i. Select the Reset entry on the left.
• The window displays as shown:
• Note the options on this window.
j. Select Cancel to close the window and return to the main Network Settings window.
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5. Use the Network Settings window to add a profile.
a. Select the Add Profile button as shown:
• The window displays as shown:
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b. Select the Identity entry on the left.
• The window displays as shown:
c. Provide the following Identity information:
• Name: new_eth1
• MAC Address: Select eth1 from the drop-down list.
• Accept remaining defaults.
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• Your window appears as shown:
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d. Select the IPv4 entry on the left.
• The window displays as shown:
• Do not make any changes on this window.
• Use DHCP to obtain an IP address from the DHCP server, dom0.
• Dynamic Host Configuration Protocol (DHCP) is covered in another course.
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e. Click Add.
• The New Profile window closes.
• The Network Settings window displays as shown.
• Ensure the Ethernet (eth1) entry on the left is selected.
• Note that eth1 has a check mark meaning it is currently the selected profile.
6. Use NetworkManager to select a different connection profile.
a. Select the computer screen icon to display the following:
• Note that two connections are listed for the Ethernet (eth1) entry.
• Note that the eth1 entry has a dot meaning it is currently selected.
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b. Click the new_eth1 entry.
• Select the computer screen icon again to show that new_eth1 now has a dot meaning it is currently selected.
• Notice that the new_eth1 entry is also selected in the Network Settings window.
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...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 00:16:3e:00:02:03 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.254/24 brd 192.168.1.255 scope global eth1 inet6 ...
...
• Note that the eth1 interface now has different IPv4 address.
• In this example, the IPv4 address is 192.168.1.254.
• This address might be different on your system because it was obtained from the DHCP server running on dom0.
7. View the network interface configuration file for the new connection profile.
a. From a command window, use the cd command to change to the /etc/sysconfig/network-scripts directory.
# cd /etc/sysconfig/network-scripts
b. Use the ls command to display files beginning with “ifcfg”.
# ls ifcfg*
ifcfg-eth0 ifcfg-eth1 ifcfg-lo ifcfg-new_eth1
• Note that the ifcfg-new_eth1 file exists for the new connection profile.
c. Use the cat command to view the contents of the ifcfg-new_eth1 file.
# cat ifcfg-new_eth1
• Note that this Ethernet interface uses DHCP to obtain an IPv4 address:
• BOOTPROTO=dhcp 8. Close the Network Settings window.
Click the X in the upper-right corner of the Network Settings window.