Chapter 26. Configuring a static route

Procedure

1. Add the static IPv4 route to the LAN connection profile:

   # nmcli connection modify LAN +ipv4.routes "198.51.100.0/24 192.0.2.10"

   To set multiple routes in one step, pass the individual routes comma-separated to the command:

   # nmcli connection modify <connection_profile> +ipv4.routes "<remote_network_1>/<subnet_mask_1> <gateway_1>, <remote_network_n>/<subnet_mask_n> <gateway_n>, ..."

2. Add the static IPv6 route to the LAN connection profile:

   # nmcli connection modify LAN +ipv6.routes "2001:db8:2::/64 2001:db8:1::10"

3. Re-activate the connection:

   # nmcli connection up LAN

Verification

1. Display the IPv4 routes:

   # ip -4 route
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp1s0

2. Display the IPv6 routes:

   # ip -6 route
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp1s0 metric 1024 pref medium

Procedure

1. Start nmtui:

   # nmtui

2. Select Edit a connection, and press Enter.
3. Select the connection profile through which you can reach the next hop to the destination network, and press Enter.
4. Depending on whether it is an IPv4 or IPv6 route, press the Show button next to the protocol’s configuration area.

5. Press the Edit button next to Routing. This opens a new window where you configure static routes:

   1. Press the Add button and fill in:

      • The destination network, including the prefix in Classless Inter-Domain Routing (CIDR) format
      • The IP address of the next hop
      • A metric value, if you add multiple routes to the same network and want to prioritize the routes by efficiency
   2. Repeat the previous step for every route you want to add and that is reachable through this connection profile.

   3. Press the OK button to return to the window with the connection settings.

      Figure 26.1. Example of a static route without metric

      
6. Press the OK button to return to the nmtui main menu.
7. Select Activate a connection and press Enter.

8. Select the connection profile that you edited, and press Enter twice to deactivate and activate it again.

   Important

   Skip this step if you run nmtui over a remote connection, such as SSH, that uses the connection profile you want to reactivate. In this case, if you would deactivate it in nmtui, the connection is terminated and, consequently, you cannot activate it again. To avoid this problem, use the nmcli connection <connection_profile> up command to reactivate the connection in the mentioned scenario.

9. Press the Back button to return to the main menu.
10. Select Quit, and press Enter to close the nmtui application.

Procedure

1. On the IPv4 tab:

   1. Optional: Disable automatic routes by clicking the On button in the Routes section of the IPv4 tab to use only static routes. If automatic routes are enabled, Red Hat Enterprise Linux uses static routes and routes received from a DHCP server.

   2. Enter the address, netmask, gateway, and optionally a metric value of the IPv4 route:

      

2. On the IPv6 tab:

   1. Optional: Disable automatic routes by clicking the On button i the Routes section of the IPv4 tab to use only static routes.

   2. Enter the address, netmask, gateway, and optionally a metric value of the IPv6 route:

      

3. Click Apply.

4. Back in the Network window, disable and re-enable the connection by switching the button for the connection to Off and back to On for changes to take effect.

   Warning

   Restarting the connection briefly disrupts connectivity on that interface.

Verification

1. Display the IPv4 routes:

   # ip -4 route
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp1s0

2. Display the IPv6 routes:

   # ip -6 route
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp1s0 metric 1024 pref medium

Procedure

1. Open a terminal, and enter nm-connection-editor:

   $ nm-connection-editor

2. Select the example connection profile, and click the gear wheel icon to edit the existing connection.

3. On the IPv4 Settings tab:

   1. Click the Routes button.

   2. Click the Add button and enter the address, netmask, gateway, and optionally a metric value.

      

   3. Click OK.

4. On the IPv6 Settings tab:

   1. Click the Routes button.

   2. Click the Add button and enter the address, netmask, gateway, and optionally a metric value.

      

   3. Click OK.
5. Click Save.

6. Restart the network connection for changes to take effect. For example, to restart the example connection using the command line:

   # nmcli connection up example

Verification

1. Display the IPv4 routes:

   # ip -4 route
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp1s0

2. Display the IPv6 routes:

   # ip -6 route
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp1s0 metric 1024 pref medium

Procedure

1. Open the nmcli interactive mode for the example connection:

   # nmcli connection edit example

2. Add the static IPv4 route:

   nmcli> set ipv4.routes 198.51.100.0/24 192.0.2.10

3. Add the static IPv6 route:

   nmcli> set ipv6.routes 2001:db8:2::/64 2001:db8:1::10

4. Optional: Verify that the routes were added correctly to the configuration:

   nmcli> print
   ...
   ipv4.routes:    { ip = 198.51.100.0/24, nh = 192.0.2.10 }
   ...
   ipv6.routes:    { ip = 2001:db8:2::/64, nh = 2001:db8:1::10 }
   ...

   The ip attribute displays the network to route and the nh attribute the gateway (next hop).

5. Save the configuration:

   nmcli> save persistent

6. Restart the network connection:

   nmcli> activate example

7. Leave the nmcli interactive mode:

   nmcli> quit

Verification

1. Display the IPv4 routes:

   # ip -4 route
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp1s0

2. Display the IPv6 routes:

   # ip -6 route
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp1s0 metric 1024 pref medium

Procedure

1. Create a YAML file, for example ~/add-static-route-to-enp1s0.yml, with the following content:

   ---
   routes:
     config:
     - destination: 198.51.100.0/24
       next-hop-address: 192.0.2.10
       next-hop-interface: enp1s0
     - destination: 2001:db8:2::/64
       next-hop-address: 2001:db8:1::10
       next-hop-interface: enp1s0

   These settings define the following static routes:

   • An IPv4 route to the remote 198.51.100.0/24 network. The corresponding gateway with the IP address 192.0.2.10 is reachable through the enp1s0 interface.
   • An IPv6 route to the remote 2001:db8:2::/64 network. The corresponding gateway with the IP address 2001:db8:1::10 is reachable through the enp1s0 interface.

2. Apply the settings to the system:

   # nmstatectl apply ~/add-static-route-to-enp1s0.yml

Verification

1. Display the IPv4 routes:

   # ip -4 route
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp1s0

2. Display the IPv6 routes:

   # ip -6 route
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp1s0 metric 1024 pref medium

Procedure

1. Create a playbook file, for example ~/playbook.yml, with the following content:

   ---
   - name: Configure the network
     hosts: managed-node-01.example.com
     tasks:
       - name: Ethernet connection profile with static IP address settings
         ansible.builtin.include_role:
           name: rhel-system-roles.network
         vars:
           network_connections:
             - name: enp7s0
               type: ethernet
               autoconnect: yes
               ip:
                 address:
                   - 192.0.2.1/24
                   - 2001:db8:1::1/64
                 gateway4: 192.0.2.254
                 gateway6: 2001:db8:1::fffe
                 dns:
                   - 192.0.2.200
                   - 2001:db8:1::ffbb
                 dns_search:
                   - example.com
                 route:
                   - network: 198.51.100.0
                     prefix: 24
                     gateway: 192.0.2.10
                   - network: 2001:db8:2::
                     prefix: 64
                     gateway: 2001:db8:1::10
               state: up

   For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

2. Validate the playbook syntax:

   $ ansible-playbook --syntax-check ~/playbook.yml

   Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

3. Run the playbook:

   $ ansible-playbook ~/playbook.yml

Verification

1. Display the IPv4 routes:

   # ansible managed-node-01.example.com -m command -a 'ip -4 route'
   managed-node-01.example.com | CHANGED | rc=0 >>
   ...
   198.51.100.0/24 via 192.0.2.10 dev enp7s0

2. Display the IPv6 routes:

   # ansible managed-node-01.example.com -m command -a 'ip -6 route'
   managed-node-01.example.com | CHANGED | rc=0 >>
   ...
   2001:db8:2::/64 via 2001:db8:1::10 dev enp7s0 metric 1024 pref medium