Android phone has Wi-Fi troubles after subnet change

Question

I just moved our network access point to a different subnet (which has a different default gateway). After the change, all the laptop computers adjusted without much issue (some XP computers needed the "repair" option run on the connection). However, none of the Android phones have Internet access anymore. They can connect to the wireless access point without a problem, but they can't access the Internet. This only seems to happen on the Android phones. I am wondering if maybe it remembers the old settings and isn't picking up the new default gateway? What can I do to fix this?

Answer 1

Turns out it was a problem with the DNS servers my DHCP was serving up. The first two were local DNS servers. I don't know why they weren't working for android (they worked fine for the laptop computers), but as soon as I replaced the second local DNS server with a remote DNS server, things started working. It also appears that android only pays attention to the first two servers given by DHCP since I had other servers listed after my local server.

It seems kind of fishy that only the android phones had problems with the local DNS server. I wouldn't mind finding out what the underlying problem is, but changing the DNS servers is an acceptable workaround.

Answer 2

Most likely, the device is still hanging out to the old network configuration and needs to be adjusted or cleared. There are a couple of methods that can be used to accomplish this. Lets start from the simplest:

1. Reset the device Wi-Fi connection.

   Simple Wi-Fi connection reset, by turning off wireless and then turning it back on:

   1. Tap the Menu button on your device;
   2. Tap "Settings";
   3. Tap "Wireless and Network";
   4. Tap "Wi-Fi settings";
   5. In the new screen, uncheck Wi-Fi to turn it off;
   6. After Wi-Fi is turned off, tap the entry again to turn it back on.

   Test your connection to confirm if this worked. If not, continue to the next options.

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2. Forget about the network

   You can have your device forget the network and then re-add it, but for this to be possible, it needs to get out of range of the network, then:

   1. From the previous location, long press the network you want to forget;
   2. Tap over "Forget Network";
   3. Get back within range, wait for the network to show up;
   4. Enter the network password to join.

   At this point your device should have a new address and be working.

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3. Advanced Wi-Fi settings

   At this point is clear that you need to confirm all settings for your Wi-Fi connection:

   1. Tap the Menu button on your device;
   2. Tap "Settings";
   3. Tap "Wireless and Network";
   4. Tap "Wi-Fi settings";
   5. Tap the Menu button again;
   6. Tap "Advanced";

   From here you can confirm all the settings one by one and make sure they match your network requirements:

   Use static IP address, Network Gateway, Netmask, DNS1 and DNS2.