We recently released an android application that pulls information from an external server. Last week we moved from shared hosting to a dedicated server, that went smoothly up until we started getting complaints that users were getting server not found errors. We checked on our android-based phones (Droid) and everything worked fine. The vast majority of users are fine, there seems to be a small percentage of t-mobile users running android o/s 1.5 (g1, mytouch 3g) that seem to be having trouble. We believe these are all previous users of the application.
Anyway, we've been trying to find a fix (similar to ipconfig /flushdns) but have been unable to do so. Has anyone had experience with something similar to this? Thanks.
copied from: https://android.stackexchange.com/questions/12962/flush-clear-dns-cache
Addresses are cached for 600 seconds (10 minutes) by default. Failed lookups are cached for 10 seconds. From everything I've seen, there's nothing built in to flush the cache. This is apparently a reported bug http://code.google.com/p/android/issues/detail?id=7904 in Android because of the way it stores DNS cache. Clearing the browser cache doesn't touch the DNS, the "hard reset" clears it.
Perform a hard reboot of your phone. The easiest way to do this is to remove the phone's battery. Wait for at least 30 seconds, then replace the battery. The phone will reboot, and upon completing its restart will have an empty DNS cache.
Read more: How to Flush the DNS on an Android Phone | eHow.com http://www.ehow.com/how_10021288_flush-dns-android-phone.html#ixzz1gRJnmiJb
Source: Stackoverflow.com