One such configuration option is called AP Isolation, sometimes called Client Isolation. AP Isolation will completely break Photosmith sync with Lightroom.
In computer networking lingo, “AP” stands for Access Point, or in this case, a Wi-Fi Access Point. So, in essence, AP Isolation effectively creates a “private” network among different wireless clients, in which each device is an individual entity that cannot communicate with other wireless devices that also connect to the same Wi-Fi Access Point. This “private” configuration can be very useful for public Wi-Fi hotspots, to help separate potentially malicious network traffic from each other.
Think about it: When you’re connected to a public hotspot, you usually only want a connection to the Internet, not to other devices also connected to the public Wi-Fi hotspot. However, in the case of Photosmith sync, you do want two devices, your Mac or PC and iPad, to talk to each other and exchange information. Thus, by its very nature and purpose, AP Isolation will break Photosmith sync by actively preventing your Mac or PC and iPad from exchanging data.
AP Isolation has become the standard network configuration for public Wi-Fi hotspots, such as Internet cafés, coffee shops, and public transit like buses, trains and airplanes. Sometimes, corporate and school/university networks also have AP Isolation enabled. If you are connected to a public Wi-Fi hotspot and are unable to get get Photosmith sync working, this is very likely the cause.
Disabling AP Isolation
On your home network with Wi-Fi encryption (WPA or WPA2) enabled, AP Isolation doesn’t make a lot of sense to have enabled, as you have direct control about which wireless devices, and there's a very low probability of the Bad Guys getting in and doing Bad Things.
Below, we discuss how to toggle AP Isolation on and off, based on a few popular router firmwares. .
DD-WRT is an advanced, very configurable firmware that can be loaded on many brands of routers, and now comes pre-loaded on some routers/access points from Buffalo Tech.
AP Isolation may be configured in DD-WRT firmware via Wireless -> Advanced Settings:
Tomato firmware is another very sophisticated custom firmware which may be loaded onto many Broadcom-based routers.
AP Isolation is configured in Tomato via Advanced -> Wireless:
Apple Airport Express, Airport Extreme
Apple's Airport line of wireless networking hardware (Airport Express, Airport Extreme) do not support AP Isolation. Thus, this is not an issue for users with Apple Wi-Fi hardware.