# CFHostGetReachability(_:_:) Gets reachability information from a host. ``` func CFHostGetReachability(_ theHost: CFHost, _ hasBeenResolved: UnsafeMutablePointer?) -> Unmanaged? ``` ## Parameters `theHost` The host whose reachability is to be obtained. The host must have been previously resolved. (To resolve a host, call [`CFHostStartInfoResolution(_:_:_:)`](/documentation/CFNetwork/CFHostStartInfoResolution(_:_:_:)).) This value must not be `NULL`. `hasBeenResolved` On return, contains `TRUE` if the reachability was available, otherwise `FALSE`. This value may be `NULL`. ## Return Value A CFData object that wraps the reachability flags (`SCNetworkConnectionFlags`) defined in `SystemConfiguration/SCNetwork.h`, or `NULL` if reachability information was not available. ## Discussion This function gets reachability information in a thread-safe way, but the resulting data is not thread-safe. The data is returned as a “get” as opposed to a copy, so the data is not safe if the CFHost is altered from another thread. --- 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)