I have a HTTP and Websocket server running on laptop1 (on ports 8070 and 8080 respectively, serving a web app via HTTP which then connects to the WS server to get state updates) and I’m connecting to it from laptop2 (loading the web app in Firefox and Chrome). The browser can fetch the web app and assets just fine, but the WS connection ONLY works over my Lancom router (has ethernet only, no wifi), NOT over Linksys WRT 54G (tested both ethernet AND wifi) or TP-LINK MR3020 (wifi-only travel router), for those I always get timeout for the WS connection attempt.
Any idea why it doesn’t work over those routers?
The use case that I need to work is: Using the web app on my android tablet to communicate with the backend on my laptop1 when I'm traveling (using the TP-Link MR3020 router), so I'm trying to figure out why the websocket connection doesn't work over the wifi routers.
A few months ago I was using my neighbor’s wifi and it was working over that (between my tablet and laptop, also between both laptops), but he had a different (large) router and I need it to work with the TP-LINK MR3020 travel router because I need a portable setup.
(After my neighbor moved away (so I wasn’t using his router between my tablet and my laptop anymore, and tried the TP-LINK MR3020) I first noticed that it wasn’t working there, so I tried between both laptops and there I saw that I was getting timeouts in the browser dev console…)
This is driving me mad, any idea why I’m always getting timeouts with websockets, EXCEPT over ethernet with the Lancom router (even over ethernet with the Linksys router)?
And btw, I did try different ports for the websocket server (e.g. 8077) thinking that maybe the router was using that port for itself, but I’m getting the same results (WS connection timeouts) :(
What else can I try?
It’s not a Windows Firewall issue (laptop1 is running Windows 8.1 and I explicitly allowed this app to listen on ports on public and private networks), not a wifi issue (it was working with my neighbor’s Fritzbox router), and it works over ethernet with the Lancom router but not with the Linksys, what could be the cause?
And how are websockets so special that a router can let normal HTTP traffic through but not Websockets?
How can I find out exactly at which point in the chain the WS connection fails, to get to the bottom of this?
Thanks!
