Reachability - earlier versions

I would alert the user when the connection with a web server is lost. I t开发者_JAVA百科hink the Apple Reachability class could solve my problem, but I would build for ios < 4.

So, my question is: where could I find earlier version of reachability?

Is it possible to build for ios < 4 with reachability ver 2.1?

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yes, why not, I think the Reachability code does not change much, you just need to select your build deployment target to the earlier version, keeping the base SDK to the latest one, and you are fine.