How to troubleshoot connectivity issues

Connectivity issues with Microsoft Flight Simulator can be caused by many different things. The suggestions below are listed in order of what we've noticed solves the most frequent causes of connectivity issues. Start from the top and work your way through the list. 

PLAY ON A WIRED CONNECTION

If you're using Wi-Fi, switch to an LTE or wired connection. This will help ensure that you are on a stable internet connection. A wired connection greatly reduces the risk of your internet connecting and disconnecting continuously. 

IMPROVE THE CONNECTION PERFORMANCE

Disconnect other devices from the network to improve connection performance. Streaming and downloading both tie up bandwidth and slow down your connection speed, which can cause problems with Microsoft Flight Simulator. This slow down happens even if you are streaming or downloading on a different device than the one you are playing on. Stopping streams, downloads, and turning off other devices can improve your Microsoft Flight Simulator. connection a great deal.

CHECK YOUR REGION SERVER 

It may sound too simple but try choosing the region closest to you to improve your connection, performance and speed:

1. Launch Microsoft Flight Simulator
2. Click on your icon & gamertag in the top right-hand side corner of the screen
3. Select the scrolling menu under Servers
4. Select your region

RESTART YOUR MODEM OR ROUTER

Restarting the modem or router can clear up most connection issues.

1. Shut down your computer
2. Unplug the modem and router (if you have a router) from the power source
   All the lights on the modem and router should be off
3. Leave unplugged for about a minute
4. Plug the modem back into the power source
5. Wait until the Internet/Wi-Fi light turns green or stops blinking (typical with most modems, although some may not have these lights)
6. If you have a router, plug it back into the power source. Wait about a minute for it to connect.
7. Turn your computer back on
8. Launch Microsoft Flight Simulator

TRY A VPN 

You may be in a remote location or your bandwidth may be throttled. Try using a VPN (you can find free trials online) to connect to another datacenter or prevent your ISP from seeing what kind of traffic is coming and going on your line. 

FLUSH YOUR DNS CACHE

• Close Microsoft Flight Simulator
• In the Windows Search bar type "CMD"
• Right-click on Command Prompt and click Run as administrator.
• In the console, type the following command: ipconfig /flushdns. If the command was successful, you will see the message "Successfully flushed the DNS Resolver Cache":
• Reboot your computer
• In the "Type here to search" bar in the bottom let the corner of the screen, next to the Start menu, type Microsoft Flight Simulator
• Select Run as administrator to launch the sim.

USE GOOGLE PUBLIC DNS

No one is immune to issues with their ISP’s DNS server. Change your DNS to Google Public DNS and try again.

DNS settings are specified in the TCP/IP Properties window for the selected network connection.

Example: Changing DNS server settings on Windows 10

1. Go to the Control Panel.
2. Click Network and Internet > Network and Sharing Center > Change adapter settings.
3. Select the connection for which you want to configure Google Public DNS. For example:
   
   • To change the settings for an Ethernet connection, right-click the Ethernet interface and select Properties.
   • To change the settings for a wireless connection, right-click the Wi-Fi interface and select Properties.
4. Select the Networking tab. Under This connection uses the following items, select Internet Protocol Version 4 (TCP/IPv4) or Internet Protocol Version 6 (TCP/IPv6) and then click Properties.
5. Click Advanced and select the DNS tab. If there are any DNS server IP addresses listed there, write them down for future reference, and remove them from this window.
6. Click OK.
7. Select Use the following DNS server addresses. If there are any IP addresses listed in the Preferred DNS server or Alternate DNS server, write them down for future reference.
8. Replace those addresses with the IP addresses of the Google DNS servers:
   
   • For IPv4: 8.8.8.8 and/or 8.8.4.4.
   • For IPv6: 2001:4860:4860::8888 and/or 2001:4860:4860::8844.
   • For IPv6-only: you can use Google Public DNS64instead of the IPv6 addresses in the previous point.
9. Test that your setup is working correctly; see Test your new settings.
10. Repeat the procedure for additional network connections you want to change.

Source

ENABLE PORT FORWARDING

In some cases, your router may be blocking communication with Microsoft Flight Simulator servers. Unable to Connect is a typical error message associated with this issue. To resolve this, you may need to manually forward these ports.

Every router is a little different. If you run into problems with this guide, try searching your routers’ support site for a more detailed guide on Port Forwarding.

1. Open your Web Browser (ex. Microsoft Edge, Firefox, etc.)
2. Type your Default Gateway into the URL Address bar to Access Your Route
   • You may be prompted with a popup window requesting your Username and Password
   • Check your router manual for info on the default gateway
3. Look for the Port Forwarding page once you have you are on your router’s configuration page
4. Add entries for Microsoft Flight Simulatorusing the following port ranges:
   • TCP: 3074
   • UDP: 88, 3074, 30000 to 31000.

Port forwarding will not improve the quality of your connection to the game servers. It will only help in cases where you are unable to contact the Microsoft Flight Simulator servers while you are online.

RESET OR REINSTALL NETWORK ADAPTER

There is a simple way to reset all your network settings to default. Warning: After going through the steps below, your computer will reset all your network settings and forget saved Wi-Fi passwords. All your network connections need to be reconfigured.

• In the Cortana search bar type "Network reset"
• Click the Reset button
• Reboot your computer