# CFNetServiceMonitorStop(_:_:) Stops a CFNetServiceMonitor. ``` func CFNetServiceMonitorStop(_ monitor: CFNetServiceMonitor, _ error: UnsafeMutablePointer?) ``` ## Parameters `monitor` CFNetServiceMonitor, started by calling [`CFNetServiceMonitorStart(_:_:_:)`](/documentation/CFNetwork/CFNetServiceMonitorStart(_:_:_:)), that is to be stopped. `error` Pointer to a structure or `NULL`. For synchronous monitors, set the `error` field of this structure to the non-zero value you want to be set in the `CFStreamError` structure when [`CFNetServiceMonitorStart(_:_:_:)`](/documentation/CFNetwork/CFNetServiceMonitorStart(_:_:_:)) returns. Note that when it returns, [`CFNetServiceMonitorStart(_:_:_:)`](/documentation/CFNetwork/CFNetServiceMonitorStart(_:_:_:)) returns `FALSE.` If the monitor was started asynchronously, set the `error` field to the non-zero value you want the monitor’s callback to receive when it is called. If this parameter is `NULL`, default values for the `CFStreamError` structure are used: the domain is set to `kCFStreamErrorDomainNetServices` and the error code is set to `kCFNetServicesErrorCancel`. ## Discussion This function stops the specified monitor. Call [`CFNetServiceMonitorStart(_:_:_:)`](/documentation/CFNetwork/CFNetServiceMonitorStart(_:_:_:)) if you want to start monitoring again. If you want to stop monitoring and no longer need to monitor record changes, call [`CFNetServiceMonitorInvalidate(_:)`](/documentation/CFNetwork/CFNetServiceMonitorInvalidate(_:)) instead of this function. ### Special Considerations This function is thread safe. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)