• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Help Assigned Static IP Address with Ethernet Adapter Does Not Work

A

ADynes

Lurker
I have a Galaxy Tab S2 running the latest Android available for it. We purchased a Lava TL-002 SimulCharge USB adapter (http://www.lavalinkstore.com/catalog/index.php?main_page=product_info&products_id=74) and a USB Ethernet adapter. We plugged everything together and plugged the ethernet adapter into a router and it got a IP address through DHCP and worked great. We then tried to set a static IP address and it will NOT work. No static IP address we set works but DHCP works fine.

We tried setting a simple 192.168.1.10 for the tablet and then a 192.168.1.20 for a PC and we could not ping back and forth. We then turned on DHCP and the tablet got a 192.168.1.100 and the PC got 192.168.1.101 and we could ping.

For our application we do not want a router, we want hard coded IP addresses. Has anyone heard of this limitation or have any idea where I would go for help? This is a stock tablet with all updates done (OS updates) and no applications downloaded (no GMail account even added). We have tried multiple USB -> Ethernet adapters (USB 2, 3, 10/100, gig, etc) all with the exact same results. We have tried multiple cables and switches. I cannot fault the Lava adapter since it works fine with DHCP so I'm assuming its a issue with the Android OS itself.

Any ideas?

-Allan
 
What make/model router are you using?
I'm wondering if this isn't so much a problem with your Tab or with Android but something with the router, or more specifically some random configuration setting in your router. At home I have DHCP enabled but a number of things connected to my router use only reserved IPs, including my phone that's using WiFi, not any kind of adapter/patch cable so this is definitely a loose comparison. Still, I don't encounter any issues connecting my phone to DHCP-assigned or reserved IP addresses elsewhere.
If you try enabling DHCP again and reserving an IP for your Tab does this make any difference? I know you mentioned wanting to eliminate any kind of routing functions and just use assigned IPs but just curious if this works out, then you can move on from there.
Also, when you've been doing your tests and changing from DHCP to assigned addresses, are you doing anything to reset the network settings on your Tab? While they typically reconfigure themselves automatically as you move between different networks or between changes in WiFi to cellular, I don't know if the IP change works out in a similar way when using a daisy-chain of hardwire based adapters. Are you rebooting the Tab between changeovers or using some network app?
 
Make and model of the router shouldn't matter at all since it doesn't work with a standard switch or hub. You should be able to set a static IP address on two devices and ping each other without a issue but I cannot set a static address on the android tablet that actually works.

As for the tab I'm turning off Ethernet (checkbox) then clicking Static IP and changing the address then turning Ethernet back on. The link lights up both on the adapter and on the tab, it just doesn't work.
 
Have you tried rebooting your Tab in between changing over from DHCP to assigned? There might be something else retaining the old IP address as the different IP addresses are being done through that not-as-common set of adapters. Or a similar test would be to use the same assigned IP address as what your Tab is being given using DHCP.
 
No. However there is a work around. Set the default gateway to the device you are trying to connect to.

So if the tablet is 192.168.1.20 and the device you are trying to talk to is 192.168.1.40 then the tablet should look like this:

IP: 192.168.1.20
SM: 255.255.255.0
GW: 192.168.1.40

For us its working since we are using the tablets as a display for a device that has a built in web server.

Apparently the Android network stack isn't as robust as a computer and for whatever reason seems to require a gateway that replies. So for a situation like we have this workaround is ok. Otherwise we will put in some really cheap $30 - $40 routers that have DHCP built in which will also work.

-Allan
 
Last edited:
ADynes said:
So if the tablet is 192.168.1.20 and the device you are trying to talk to is 192.168.2.40 then the tablet should look like this:

IP: 192.168.1.20
SM: 255.255.255.0
GW: 192.168.1.40
Click to expand...

With a device using an IP of 192.168.1.20 and another device using 192.168.2.40 they're essentially on different networks.
Setting your LAN to use a subnet of 255.255.252.0 that should allow you to use a range of 192.168.1.1 to 192.168.2.254
 
I'm sorry, thats a typo. They are both on the 192.168.1.0 subnet. I updated the post. The Android device still requires a gateway even if not technically needed....its like it ignores the subnet mask.
 
ADynes- I greatly appreciate your response.

We are trying to connect a Galaxy S2 over ethernet to various devices using PLUGABLE USB 2.0 OTG MICRO-B TO 10/100 ETHERNET ADAPTER(http://plugable.com/products/usb2-otge100). We have also been successful connecting through DHCP but have had no success setting a static IP. Prior to your confirmation, I have only been able to find people saying that Android does not support static IP addresses on Ethernet. We have more testing to do. I will try your settings and post another response.
 
My attempts were with a LAVA TL-002 Simucharge adapter which lets you charge the tablet and have a open USB port simultaneously (http://lavalink.com/samsung-tablet-adapters/tl-002/). The adapter I used was a Able Conn USB2E100B USB to Ethernet (https://www.amazon.com/Ableconn-USB2E100B-Ethernet-ChromeBook-Specific/dp/B005UFO1FA) . I tried a couple other USB to Ethernet adapters and had the same results. Same adapter on a PC had no issues without a assigned gateway pinging the device we are tryin to connect to which led me to assume the android network stack is just lacking. It would be nice if you found the exact same results at least as confirmation.

-Allan
 
Tbonecarr said:
I have only been able to find people saying that Android does not support static IP addresses on Ethernet.
Click to expand...

That's very likely, as Android was designed from the outset as a 'wireless' platform.

It supports static addressing over wifi, but to do the same via ethernet you'll need to configure things manually at the router/AP end by assigning IPs to unique MAC addresses. To avoid premature hair loss, ensure that the range of static IPs is excluded from those in the DHCP pool.... I missed that once and the results were not pretty. :oops:
 
You must log in or register to reply here.
Back
Top Bottom