[Networking] bmx0964:
Here is basically a run-down of what I did. I hope this helps everyone out.

Device specs:

Samsung Galaxy Player 4.0 Rooted

Network Specs:

DSL Modem

Router (DHCP with WPA security and does not have MAC Filtering)

4 Access Points (all on same channel broadcasting same SSID with same WPA security DHCP)

2 Servers - Static IPs

-Server 1 - DNS (not sure if it is actually a DNS server or just forwards the requests). Also storage/application server.

-Server 2 - Storage/Application/SQL server

Many clients on network (unsure of total amount but somewhere around 30 would be my guess)

Problem (note this is only on this network, every other network wifi

works just fine):

Wifi Connected but no internet.

My Windows 7 laptop (same network) gets internet access with no problems

No reports of any other clients on the network having this issue

Device has assigned a good DHCP IP address

Subnet, Gateway, and DNS IPs are all correct (they match the ones on my laptop)

Connection strength is great (speed is 52mbps)

Device has full local access (intranet). It can access all files and other devices on the network.

On occasion the device will get "internet" access for a brief period of time but will go back to "intranet" access only after a few minutes.

Tests Performed (My android device will be referred to as "device" my laptop will be reffered to as "laptop". All tests were performed with both laptop and device connected to the network in question, unless otherwise specified, and device was not able to access internet):

Ping from laptop to device - Successful

Ping from device to laptop - Successful

Ping from laptop to gateway - Successful

Ping from device to gateway - Failed

Resolve DNS IP on device - Successful

Resolve DNS IP on laptop - Successful

Ping from laptop to google - Successful

Ping from device to google - Failed

Small FTP file transfer from laptop to device - Successful

Small FTP file transfer from device to laptop - Successful

Device has no problems on other networks (tried un-secured, WEP, and WPA/WPA2)

Connect device using Google public DNS servers

-Intranet - Successful

-Internet - Failed

-Resolve DNS IP - Successful

Connect laptop using Google public DNS servers

-Intranet - Successful

-Internet - Successful

-Resolve DNS IP - Successful

More that I cannot remember right now. Will add as they come to me.

At this point I gave up for a few days. Every test and every bit of research returned nothing. I had spent many many hours trying to figure this out and testing theories and nothing ever pointed me in the right direction of where to go. Nothing made sense EVERY single setting is the same is on my laptop. Started thinking maybe there was something in the router that could be blocking Android devices (since it is a work network). Although I am not a aware of a router feature to do that I figure I would try some more tests.

Testing Round 2 (same conditions as initial tests):

Configured laptop to be a Wifi hotspot.

-From CMD command 1: netsh wlan set hostednetwork mode=allow ssid=AP key=XXXXXXXXX

-From CMD command 2: netsh wlan start hostednetwork

-From network and sharing center: Shared the physical wireless network connection with the Microsoft Virtual WiFi Miniport Adapter.

-The above commands create a virtual wireless adapter and set it broadcast the specified SSID with the specified WPA security key. Then you can choose any available, connected, physical, internet connection and share it's internet connection with the virtual connection, thus theorectically turning my laptop into a 5th access point on the network.

Connected device to the SSID "AP"

-Intranet - Successful

-Internet - SUCCESSFUL

Horray!!!! Progress! So with the above information I went to our IT guy and we sat down and looked at some stuff (settings in the router, access points, and servers). After digging and digging around within the settings we came up with.... you guessed it NOTHING!!!!!!!!!!!!! Now I was in "Its on!" mode and decided I wasn't going to stop until I found out at least what was causing the problem. My IT guy was also very determined to figure this out as he doesn't like to get beat either. So we both went at it. We decided the first thing to do was make a very detailed network map containing every piece of information we could possibly find. We did this all from his machine (laptop with Windows 7) and wrote everything down on paper (we even used a piece of our 36" wide roll paper from our plotter to make sure everything would fit) and made an excel spredsheet with all the info. Now with the newly aquired network information I decided I was going to do more testing.

Testing Round 3 (same conditions as initial test):

Map the entire network again gathering every piece of information possible just like before but this time using MY DEVICE (not my laptop).

Compare

Finally! I have found the problem! As stated before my device was getting the correct gateway IP (XXX.XXX.XXX.1) which is the same as my laptop). However the assigned MAC address OF THE GATEWAY (router) to my device is XX:XX:XX:XX:XX:FB but the MAC address OF THE GATEWAY (router) to my laptop is XX:XX:XX:XX:XX:FA. Got back with our IT guy and we found (by looking the router config) that the XX:XX:XX:XX:XX:FA is the LAN MAC address for the router. The XX:XX:XX:XX:XX:FB is the WAN MAC address for the router.

Testing Round 4 (same conditions as intial test):

Connected laptop to network, confirmed XX:XX:XX:XX:XX:FA MAC address was assigned for the gateway by running "arp -a" in CMD.

-Pinged google - Passed

-Changed assigned MAC address of gateway by running "arp -s XXX.XXX.XXX.1 XX:XX:XX:XX:XX:FB" in CMD

-Verified new MAC address assignment by running "arp -a" in CMD

-Pinged google - Failed

-Changed the MAC back and pinged google again - Successful

Connected device to network, confirmed XX:XX:XX:XX:XX:FB MAC address was assigned for the gateway by running "arp -a" in Terminal.

-Pinged google - Failed

-Changed assigned MAC address of gateway by running "su" then "arp -s XXX.XXX.XXX.1 XX:XX:XX:XX:XX:FA" in Terminal

-Verified new MAC address assignment by running "arp -a" in Terminal

-Pinged google - Successful

-Changed the MAC back and pinged google again - Failed

Conclusion:

For some reason the device is getting assigned the correct gateway IP but the wrong gateway MAC. This is allowing the device to connect to the network but not communicate with the router. Since it can't communicate with the router any "Internet" requests time out because the packets have to go through the router to make it to the "Internet". Since it is not blocked from the network it can still connect and communicate with other clients on the "Intranet" but not the router.

Our IT guy thinks there is a client somewhere on the network in the same subnet that is configured in this matter and it just so happens that for some reason my device is picking that up when it connects. He is going to look into it more when time permits but since we are very busy and we have already spent way too much time on this, and I now know at least what the issue is, he is going to move on for now.

Why would my device be picking up the WAN MAC address of the router?

What would be responsible for assigning a WAN or LAN MAC address?

How can I prevent this?

Has anyone ever experienced anything like this?

Temporary Solution (must be rooted):

Open your favorite terminal app on your device.

-Enter "su" (without quotes)

-Enter "arp -s [Your gateway IP here] [Your gateway's LAN MAC address here]

Browse away!!!!!