Why routing your simulator rig breaks avionics bridge packets, and how split-tunneling keeps cockpit gauges alive
Ready to route external flight data cleanly without dropping your local simulator bridge?
You spend weeks wiring up a home cockpit or setting up a clean dual-PC layout. The main simulator runs on your high-end gaming desktop, while a secondary laptop or dedicated cockpit display handles the avionics panels, electronic flight bags, and hardware gauges using FSUIPC and WideClient.
Everything tests fine at the gate. The engines start, your instruments sync up in real time, and WideClient reports a solid connection across your local network. Then, you connect your PC to a VPN—maybe to pull live weather injection from a throttled source, access an overseas dispatch server, or join an online ATC network.
Ten minutes into your climb, your secondary screens lock up.
The artificial horizon freezes, your altimeter stops moving, and your cockpit gauges desync completely. You glance at the status bar on the secondary machine, and there it is: WideClient has dropped its TCP socket connection to WideServer, cycling through repeated reconnect attempts that go nowhere.
If you build flight simulator setups, this is one of those frustrating technical bugs that makes you want to tear your hair out. You check your network cables, ping the secondary PC’s IP address, restart FSUIPC, and check your firewall rules. The local network looks completely fine, yet the telemetry bridge refuses to stay linked.
The problem is almost never FSUIPC itself. It comes down to how standard consumer VPNs manage local subnet traffic and broadcast packets.
By default, FSUIPC’s WideFS protocol relies on continuous, low-latency socket communication between the main simulator machine and the client PC. WideClient typically listens for UDP broadcast beacon packets sent across the local subnet (255.255.255.255) to discover the server, and then locks onto a persistent bidirectional TCP socket (usually on port 8002 or 9002) to stream high-frequency variables like pitch, bank, and engine readouts.
When you install a generic consumer VPN and hit connect, the software installs a virtual network adapter and aggressively modifies your Windows routing tables. Most basic VPNs take an "all-or-nothing" approach: they redirect all outbound traffic into the encrypted tunnel, often completely blinding the system to local broadcast frames or altering the primary gateway interface.
The moment your routing table shifts, the UDP discovery beacons get pulled into the VPN tunnel or dropped by the virtual adapter's firewall rules. Worse, even if you configured WideClient with a static IP address in WideClient.ini, the VPN frequently isolates the machine from the local 192.168.x.x or 10.x.x.x subnet. As soon as the main simulator stops receiving local ACK responses on the expected interface, the socket connection collapses, freezing your hardware instruments in mid-flight.
When cockpit builders run into this, their initial reaction is usually to dig through obscure forum threads and try to manually write batch files with custom persistent route add commands in the command prompt.
That approach is tedious, fragile, and breaks the second your local router reboots or assigns a new dynamic DHCP lease. Other pilots try using public proxies or free VPN extensions, which do nothing to protect raw simulator connections and often introduce severe network jitter that causes micro-stuttering in the simulator itself.
What you actually need to keep WideClient rock-solid while running a secure network tunnel is very specific: a VPN client engineered with native, reliable split-tunneling that cleanly separates external simulator traffic from local network traffic, combined with strict preservation of local subnet broadcast protocols.
This is where ONLYDOGSVPN fits cleanly into an advanced simulator setup.
ONLYDOGSVPN is built with flexible application and IP-level split-tunneling directly into its desktop client. Instead of forcing your entire PC into an isolated network tunnel that breaks your local hardware links, you can route only specific traffic—such as your external weather tools, browser sessions, or remote dispatch feeds—through the VPN tunnel, while leaving local LAN adapters completely untouched.
Because ONLYDOGSVPN preserves local broadcast and multicast routing rules, WideServer’s discovery beacons pass directly to your secondary machines without being dropped or swallowed by the virtual interface. Your TCP telemetry sockets remain pinned to your local network card, meaning your avionics displays, secondary FMC units, and physical gauges receive continuous, zero-latency data frames regardless of what the external tunnel is doing.
Equally important for cockpit builders is connection stability during long-haul flights. A transcontinental flight session can easily last six to twelve hours. If a VPN adapter experiences micro-drops or forces sudden adapter re-initializations in the background, it can trigger a cascade of Windows network state changes that drops active sockets. ONLYDOGSVPN maintains persistent, unthrottled routing paths that run quietly without interrupting secondary adapters or causing background CPU spikes.
To be completely clear, a VPN will not fix every cockpit issue, and it is important to know when not to expect miracles.
If your physical local network is unreliable—such as running WideClient over weak, wall-penetrating 2.4GHz Wi-Fi in an area with heavy channel congestion—packets will drop at the physical link layer before any software can process them. For simulator telemetry, hardwiring both machines into a Gigabit switch is always the foundational requirement.
Similarly, if your Windows Defender Firewall is explicitly configured to block incoming connections on port 8002 on either machine, or if you have misconfigured the ServerIP in WideClient.ini to an old address, a VPN cannot correct those local settings for you. Always verify that your two PCs can communicate cleanly on a plain, vanilla LAN connection first.
Building a multi-screen flight simulator should be about flying precision approaches, not constantly troubleshooting disconnected instrument displays. If running external network tools keeps knocking out your local WideClient avionics, shifting to a provider with proper split-tunneling and local subnet passthrough solves the routing conflict once and for all.