---
title: networkUnavailableReason
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/urlerror/networkunavailablereason-swift.property
---

# networkUnavailableReason

The reason the network was unavailable for a task.

## Declaration

```swift
var networkUnavailableReason: URLError.NetworkUnavailableReason? { get }
```

## Discussion

Discussion The network may be unavailable due to restrictions placed on the URLSessionConfiguration, such as allowsConstrainedNetworkAccess, allowsExpensiveNetworkAccess and allowsCellularAccess. If the error doesn’t involve network unavailability, this property is nil.

## See Also

### Error details

- [failingURL](foundation/urlerror/failingurl.md)
- [failureURLPeerTrust](foundation/urlerror/failureurlpeertrust.md)
- [failureURLString](foundation/urlerror/failureurlstring.md)
- [downloadTaskResumeData](foundation/urlerror/downloadtaskresumedata.md)
- [backgroundTaskCancelledReason](foundation/urlerror/backgroundtaskcancelledreason-swift.property.md)
- [URLError.BackgroundTaskCancelledReason](foundation/urlerror/backgroundtaskcancelledreason-swift.enum.md)
- [URLError.NetworkUnavailableReason](foundation/urlerror/networkunavailablereason-swift.enum.md)