Enable IP address forwarding for a container host

IP forwarding is disabled on some versions of Linux, which breaks IP forwarding to containers after the VM is suspended and then resumed.

Affected Linux distributions:

In the VM, navigate to the directory /usr/lib/systemd/network/

Create the directory if it doesn’t exist.
Type the following command to determine the name of the Docker interface:
```
 ifconfig
```
Typically, the host name for the Docker interface on a machine where there is only one network interface card installed, is docker0.
Create a new file named: 80-container-<interface_name>.network, where <interface_name> is the host name for the Docker interface that you determined in step 2.
In the new file, add the following content:
```
 [Network]
 IPForward=kernel
```
Restart the VM.
Verify that containers are still accessible after the VM is suspended and then resumed, by typing the following command in a terminal:
```
 sysctl net.ipv4.conf.<interface_name>.ip_forward
```
The terminal should display the status:
```
 net.ipv4.ip_forward = 1
```