MacBook Pro not roaming in a roaming network
I have a roaming network set up using an Airport Extreme and an Airport Express, but my MacBook Pro (9,1 mid 2012) refuses to automatically switch between them.
The Extreme is in the den at one end of the house and the Express is in the living room at the opposite end. When in the living room for example, using iStumbler I can clearly see the signal from the Extreme is weak (into the yellow zone in iStumbler) and the signal from the Express is very good, yet the computer will not switch. I have even set the computer right next to the Express (less than a foot away) and can leave it there for hours and it will continue using the very weak signal from the Extreme.
The same happens in reverse. If the the laptop is connected to the Express and I move into the Den, it will not switch to the Extreme even though the signal from the Express becomes very weak at that end of the house.
The only way I have found to connect to the strongest signal is to move next to the unit, then manually turn the WiFi off and back on again.
I don’t think this is an issue with network settings as nothing has changed since I had my old 2008 MacBook Pro, which did switch as I roamed around the house (although I noticed there would have to be a fairly big difference in signal strength before it would switch, but at least it worked.)
I have very little experience with networks, but I just can’t see how this can be normal, as it seems to completely defeat the purpose of a roaming network.
Can someone explain what “normal” behaviour is, and / or offer any suggestions?
MacBook Pro, OS X Mavericks (10.9.2), MacBook Pro 9,1 2.6 GHz i7