---
title: allowPostQuantumKeyExchangeFallback
framework: networkextension
role: symbol
role_heading: Instance Property
path: networkextension/nevpnprotocolikev2/allowpostquantumkeyexchangefallback
---

# allowPostQuantumKeyExchangeFallback

A Boolean value that indicates whether servers that don’t support post-quantum key exchanges can skip them.

## Declaration

```swift
var allowPostQuantumKeyExchangeFallback: Bool { get set }
```

## Discussion

Discussion This property has no effect if you don’t configure any post-quantum key exchange methods in the NEVPNIKEv2SecurityAssociationParameters. The property’s default value is false.

## See Also

### Supporting quantum-secure cryptography

- [ppkConfiguration](networkextension/nevpnprotocolikev2/ppkconfiguration.md)
- [NEVPNIKEv2PPKConfiguration](networkextension/nevpnikev2ppkconfiguration.md)