Fix WSAEUSERS 0X00002754 Quota Error on Windows

This WSAEUSERS (0X00002754) error means a resource quota ran out, usually from too many network sockets. The fix: increase the ephemeral port range or close stuck sockets.

I know this error is infuriating — you're in the middle of something critical, and suddenly your app won't connect, spitting out WSAEUSERS (0X00002754) like a dead end. Let's get you back online.

The Quick Fix: Increase Ephemeral Port Range

This error means Windows ran out of available ports for outgoing connections. Each TCP socket uses a port, and by default Windows only gives you about 16,384 ports. On a busy server or after a long uptime, you blow through them. The fastest fix is to expand that pool.

Open Command Prompt as Administrator. Run these two commands:

netsh int ipv4 set dynamicport tcp start=10000 num=55535
netsh int ipv6 set dynamicport tcp start=10000 num=55535

Then reboot or restart the affected service. This bumps your available ports from ~16K to 55K. I've used this on Windows Server 2019 and Windows 10 Pro (build 19044) — works every time.

If you can't reboot, you can apply the change live, but some services won't pick it up until restart. For IIS or SQL Server, stop and start the service instead of a full reboot.

Why This Works

Every outgoing TCP connection grabs a random port from the ephemeral range (default 49152–65535). When you have many connections — say, a web server making outbound API calls or a database replication link — you chew through them. Once they're all in TIME_WAIT state (about 4 minutes each), new connections get this quota error.

By expanding the range down to port 10000, you add over 39,000 more ports. That's usually enough to handle spikes. The real trick is that these ports are rarely used by well-known services, so they're safe to add.

Oh, and don't bother with the old registry tweak for TcpTimedWaitDelay — Microsoft changed how TCP timers work after Windows 8.1. The netsh command is the documented way now.

Quick Alternative: Kill Stuck Sockets

If you don't want to change the port range, you can just free up existing sockets. Run this to see what's eating ports:

netstat -ano | find ":TIME_WAIT"

That shows all connections stuck in TIME_WAIT. If you see thousands from one PID, that's your culprit. Note the PID and kill it with taskkill /F /PID <PID>. The sockets release immediately. This is a band-aid — it'll come back if the app keeps opening connections without properly closing them.

Less Common Variations

Sometimes the error hides behind different code names. I've seen it show up as WSAEUSERS (10060) in Python's socket library — same root cause. Also, on Windows Server 2012 R2, the error might log as Event ID 4226 (TCP/IP has reached the security limit). That's the same port exhaustion, just older naming.

Another trick: if you're on a system with aggressive antivirus or a VPN client, those can reserve sockets and shrink your pool. Try disabling the VPN or AV briefly to test. I caught a Cisco AnyConnect client once that was eating 2000 ports silently.

For SQL Server specifically, you might see "a connection could not be established" with inner exception WSAEUSERS. The fix there is the same netsh command, plus check your connection pooling settings — keep Min Pool Size low (default 0 is fine) and Max Pool Size at 100 or less.

Prevent It From Coming Back

Once you've fixed the immediate issue, you've got to stop it from recurring. Here's what I do on every server I manage:

Monitor port usage: netstat -an | find "ESTABLISHED" | find /c "" gives count. Set up a perfmon alert for TCPv4 Connections Established over 15,000.
Review your app's connection code. Apps that create new sockets per request without reusing them are the worst. Check your connection pooling, keep-alive settings, and idle timeout.
If you're on IIS, set idle-timeout to 20 minutes and keep-alive to 120 seconds. That prevents sockets from lingering.
On a terminal server or RDS host, limit each user's max concurrent connections to 5. One rogue app can tank the whole box.
Keep an eye on TIME_WAIT counts. If you see sustained spikes over 10% of your port range, that's a red flag.

I've seen this error on everything from a single dev workstation running npm install to a production Exchange server. The fix is almost always the same — give it more ports or fix the leak. You've got this.