You can set each host name to be either active or inactive at any given time. Only the active host names are actually connected to the appropriate IP addresses. If a host name in an inactive state, it is not mapped to its IP address, as if the host name were not present in the HostName Commander list at all. The check box displayed next to each host name can be used as a visual indicator of the state of that particular host name. If there is a check mark present on the checkbox, the host name is in active state. If there is no check mark displayed, the host name is in inactive state.

You can activate or deactivate all host names under the same IP address, by clicking with the mouse on the check box displayed next to the IP address (or by pressing the Space bar while the IP address is selected). After each click, the state of the check box is changing from cleared to checked to grayed and back to cleared. When the check box next to an IP address is cleared, all host names listed under that IP address become deactivated:

If you make a checkmark to appear on the box next to the IP address, all host names mapped to that IP address become active:

Finally, when you make the check box next to the IP address to be "mashed", each host name under that IP address may be activated or deactivated independently on other host names, by clicking on the check boxes next to the host names:

Note that only if the checkbox next to the IP address is "mashed" you can change the state of the individual host names under that IP address. If the checkbox next to an IP address is cleared or has a checkmark in it, it affects all host names under that IP address and prevents you from changing their states individually. When the state of a host name is controlled by its parent IP address, the background of the checkbox next to the host name becomes gray.

You may want to practice activating and deactivating the host names by clicking on the check boxes next to them as well as on those next to the IP addresses, and observe the changes caused by your actions, to get a better understanding of how the states of the host names can be changed.