A practical use for this command is on blade center switches. These commands allow the interfaces presented to the servers in the centers to see when the connection to 'the world' is down.

For example, if the switch the blade center switches connect to were suddenly down, without this command, the server would still see the blade center switch (as it's contained within the same chassis as the blades) and still try and process traffic. With this command on the interfaces facing the blades, they would track the status of the uplink and transition accordingly.

The command is "Link State Group [number] [Upstream/Downstream]". Upstream for the uplink ports and Downstream for the blade facing ports.

Of course, you can use it to perform this same function in any IOS switch.

Hope you find this helpful.