# SCNetwork ## Overview The `SCNetwork` programming interface contains functions an application can use to determine whether that application can reach a remote host and to notify the system of configuration changes. A remote host is considered reachable when a data packet, sent by an application into the network stack, can leave the local computer. Note that reachability does not guarantee that the data packet will actually be received by the host. ## Topics ### Group [`Boolean SCNetworkCheckReachabilityByAddress(const struct sockaddr *address, socklen_t addrlen, SCNetworkConnectionFlags *flags);`](/documentation/SystemConfiguration/SCNetworkCheckReachabilityByAddress) Determines whether the specified network address is reachable using the current network configuration. [`Boolean SCNetworkCheckReachabilityByName(const char *nodename, SCNetworkConnectionFlags *flags);`](/documentation/SystemConfiguration/SCNetworkCheckReachabilityByName) Determines whether the specified network host or node name is reachable using the current network configuration. [`Boolean SCNetworkInterfaceRefreshConfiguration(CFStringRef ifName);`](/documentation/SystemConfiguration/SCNetworkInterfaceRefreshConfiguration) Sends a notification to interested configuration agents to have them immediately retry their configuration over a particular network interface. ### Constants [`typealias SCNetworkConnectionFlags`](/documentation/SystemConfiguration/SCNetworkConnectionFlags) Flags that indicate whether the specified network node name or address is reachable, whether a connection is required, and whether some user intervention may be required when establishing a connection. --- 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)