If you noticed on public WIFI hotspots like coffee shops or airports, you can’t easily communicate with someone else’s computer over regular network communiction protocols. Your shared folders, for example, are not accessible by others.
You also wont be able to ping another computer on the network. All computers are isolated from each other, thus protecting them from accidental or intentional access of each other’s data.
In the popular Linksys Wireless routers (mine is a WRT54G) you can enable “AP isolation” which works by creating a separate virtual network for your wireless network. Below are the official iformation from Linksys’ help document about AP isolation:
When this feature is enabled, each of your wireless client will be in its own virtual network and will not be able to communicate with each other. You may want to utilize this feature if you have many guests that frequent your wireless network.
NOTE: The “AP” portion wasn’t defined on the Linksys documentation so we will just assume that it means Access Point.
To enable IP isolation, http://192.168.1.1 click the Wireless tab then click Advanced Wireless Settings:
Then, look for the AP Isolation dropdown on the page. By default this is turned off so just choose “On” and then click the save button:
This tip is only advisable for scenarios like in a coffee shop wherein you only need your guests to connect to the WAN gateway. In your house or private network where you would want to be able to share files between computes on the network, make sure to turn off the AP isolation settings.
Ben Carigtan shows you how it’s done.