Why can't this Asus tablet access anything over the internet though wifi is connected? I just replaced all the networking infrastructure in my home do to a Frankenstein IP packet: this includes the Arris Residential Gateway, two Netgear switches, and a Netgear Model R7000 wifi router.

Various other devices connect just fine.

But a Asus TF700T running Android 4.2.1 is not working. What's strange is that it claims to have connected, and shows an IP address.  Web pages just (eventually) time out (which is different from the immediate error I get when wifi is disconnected) and apps just hang: a blank screen on Google Store, and an empty map on Maps.

Checking the gateway, I see that IP address is listed as a client along with two IPv6 addresses at the same MAC. It does't show any other status other than lease time.

Re this post with a similar title: I have no proxy. Other (albeit newer: next oldest is 4.4.2) android devices connected in the usual way with no other configuring needed.

I am at a complete loss as to how to proceed to troubleshoot this.



update: at benjaminS’s suggestion, I tried entering a local IP address, the gateway router’s admin page, and that works.

Then I verified that my web server (at a hosting company, with a dedicated IP address) serves my personal site by default when accessed by IP address (http://199.73.30.94). On this Asus tablet, it immediatly returns the “webpage not available” page.

(Now, the page I try are failing immediatly, and Google Store quickly shows “check your connection and try again”. That is different. Settings still shows connected with local IP address.

update ⚁: ping with an ip address (for google) gives “destination Net Unreachable”. ifconfig gives no output. But I suspect at this point that the gateway is not being configured properly with DHCP.  Why not? How do I tell what's happening?

I used my phone as a hotspot and verified that stuff works in general for that device. I'm only getting E service so that's not practical for doing much. At least I can use Google Store, but please don't make me surf through the store.
The problem, it turns out, was an IP conflict, and is related to this question.

The wifi access point decided to bestow upon itself the same IPv4 address as the WAN gateway.  So, I suppose that packets were being routed to itself which had no way to continue.

(Why it was different for each device is a new mystery. Maybe newer devices use IPv6 or some other difference in the networking code?)