Windows Server 2012: DHCP: Android Clients have no access to the internet

androiddhcpdomain-name-systemwindowswindows-server-2012-r2

I am using a Windows Server 2012 R2 as Domain Controller, DHCP Server, DNS in my network. My Router is the gateway which is connected to the DSL modem.

Some Clients (all android devices) and the amazon kindle (which i think is android based as well) do not have internet access with DHCP enabled. Windows Clients, a MAC Mini, iPad and IPhone don't have any problems to access the internet, all with dhcp enabled.

If i set a static ip on the failing devices with all options manually (gateway and dns) everything is fine. So it seems to be definitly a problem of DHCP.

In DHCP options i have the following settings
Router Option 3 with the gateway address
DNS Server Option 6
DNS-Domain-Name Option 15

The following network setup

Windows Server: 10.0.1.2
Gateway: 10.0.1.1 (connected as 10.0.0.x to the modem)
Modem: 10.0.0.138
Clients: 10.0.1.100-200 = DHCP range
DHCP on Gateway router is deactivated.

NetScan shows only one dhcp server responding with the correct Gateway and DNS settings.

I can't find out whats wrong, i don't believe its a general Android problem with windows server.

Does anyone have any ideas or suggestions to solve the problem?

The failing devices seem to get a valid IP from DHCP, it seems not to be a DNS Problem, i think the gateway is not found correctly.

Best Answer

What you can do on the Android devices:

Network Tools can do a traceroute.

ipconfig will show you more network settings (like the gateway and lease duration) than the standard menus.

See what those settings are to determine whether DHCP is handing out the correct info or not.

If it looks like the device does have all the correct info (same as when you manually apply it and it works) then do the traceroute and see if that reveals anything about what the device is doing.

What you can do on the DHCP server:

In the DHCP manager, right click on IPv4, choose Properties, then go to the Advanced tab. You should see an Audit log file path which defaults to %WinDir%\system32\dhcp.

In that folder you should have detailed logs, one for each day of the week. That should help you determine what's going in a particular request.

In Event Viewer, browse to Applications and Services Logs > Microsoft > Windows > DHCP-Server. The logs in here show errors related to specific MAC addresses and requests, could be helpful.

In DHCP manager, under IPv4, check Filters and Policies to see if you have anything set in there that might be excluding Android devices (or any other settings that look interesting). For example, all android devices have a hostname that begins with Android- so you could create a policy that gives any client with an FQDN beginning with Android a different router.

Have you posted all of the DHCP options in effect (global and scope)?

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