I really need help here...
I have a simple Android application that connects to my sever to fetch data over HTTPS.
Everything is working fine up until i connected to the same server from another device (iOS or Android). I am starting to get timeouts or connection refused or other errors depending on the library that I use (sometimes SSL handshake)
I tried 2 android app on the same router - fails
I tried Volley, Retrofit, plain http library - fails
if one device is connected via cellular network and one on wifi, it is working fine. However, i have seen cases that it fails even using 2 devices connected to cellular network and not wifi.
It is easy to reproduce. one app is working fine. as soon as i do an operation on the other device. the first app will not be able to connect.
iOS app using the same api/server is working fine. no failures
I ran wireshark on the android app during failure and received the following:
70 47.073286 10.0.0.1 10.0.0.138 ICMP 120 Destination unreachable (Port unreachable)
Seems like port issues. I am not sure anymore if this is a server issue or a client issue.. iOS app works fine. no issues. Only Android.
I tried:
System.setProperty("http.keepAlive", "false");
I tried setting an http header "connection :close" nothing works...
Any idea would be appreciated...
Same problem here . When my ios device connect to allstar heroes or fun run application the android device cant connect anymore . I cant find s fix for that . My router is tp link dir 615 . Maybe the problem is frpm router .
At the end of the day, it was server side issue. the IT guy gave me the following info: "incorrect flag on the tcp kernel settings" "Reuse connection" that is all I have for you. hope it can help someone else
I had the same problem. The issue seemed to be when the app tried to access ports in TIME_CLOSE here is a great explanation how this happen, changing the tcp kernel to Reuse connection, might solve the problem since the server will try to re-use those connection in TIME_CLOSE again. but it must be a solution from the client side to avoid the connection to get stuck. in my case I was trying to create connection from multiples activities and i guess they, somehow, competed for opening and closing the connections, i solved the issue using a single activity to make the connection to the server.
hope this is useful to someone.
Had exact the same issue and spent a lot of time investigating, nothing helped including "Reuse connection" flag, tried also to disable tcp_timestamp, tcp_tw_reuse, tcp_tw_recycle and enable vm safe mode for the app as suggested here:
- https://github.com/square/okhttp/issues/903
- https://github.com/square/okhttp/issues/1037
- https://github.com/square/okhttp/issues/1518
but all in vein.
Further more, the very strange thing was that I had two different instances/servers which I made exactly the same in order to track down the issue and one server didn't have any issues.
So in the end:
Instance reboot solved problem with connections. (or just need to restart networking service)
(c) My server/instance admin
来源：https://stackoverflow.com/questions/28623779/android-http-connection-multiple-devices-cannot-connect-the-same-server