Connection Issues
If you are having problems connecting to rooms try the following things
https://www.haxball.com/webrtcdiagnostics
This page will run a set of diagnostic tests regarding WebRTC, the expected results are:
- Srflx candidates found: YES
- Host candidates found: YES
- Symmetric NAT found: NO
Users that have Symmetric NAT will be unable to join rooms hosted by other users that also have Symmetric NAT. This is a router problem.
If no Srflx candidates and no Host candidates are found it's likely that your browser is blocking WebRTC.
Some ad blockers or extensions will prevent webrtc from connecting, see if disabling the ad blocker fixes the problem.
If you normally use Chrome, try installing Firefox and trying with that. If you use Firefox then try installing Chrome.
If your computer has a public internet ip then this privacy feature can cause problems connecting to others.
Go to the url chrome://flags/ and disable the feature called 'Anonymize local IPs exposed by WebRTC'.
If you're on Firefox 74 or later, go to about:config and find media.peerconnection.ice.obfuscate_host_addresses.whitelist.
Edit or double-click to add www.haxball.com domain.
Some routers allow you to configure the NAT behaviour, the name of this setting can vary between routers. Look for the words:
- full-cone
- restricted-cone
- port-restricted-cone
- NAPT
- symmetric-nat
They are ordered from best mode to worst mode.
Most routers don't have this option so don't get your hopes up.
Enabling DMZ and pointing it towards your computer can improve the symmetric nat situation. For this you will need to set up your computer to use a static ip address instead of dynamically obtaining one with DHCP.
Keep in mind that DMZ makes your computer more accessible to the internet which is generally bad for security.
If you are using windows vista or higher the ephemeral port range is 49152 to 65535.
Forwarding UDP in this range to your computer might improve the situation. For this you will need to set up your computer to use a static ip address instead of dynamically obtaining one with DHCP.
If your home network has more than router between the internet cable and your computer then try connecting your computer to the first router. The less routing the better.
If you are fine with having a single computer connected to the router, then setting it as bridge will get rid of NAT and probably improve the situation.
If all else fails then you can try replacing the router for a different model. Sadly the NAT mode is usually not advertised so there's no good way to know if the router works properly without trying it.