We are building a VPN using NEPacketTunnelProvider where the intent is to route HTTP/S traffic through a local proxy server, while non-HTTP/S traffic flows directly to the network without being tunnelled at the IP layer. The configuration claims no included IP routes — it relies entirely on NEProxySettings to intercept HTTP/S traffic via the URL loading layer. private func configureIPSettings(_ settings: NEPacketTunnelNetworkSettings) { settings.ipv4Settings = NEIPv4Settings( addresses: ["192.168.1.1"], subnetMasks: ["255.255.255.255"] ) // No includedRoutes set — no IP traffic enters the tunnel } private func configureProxySettings(_ settings: NEPacketTunnelNetworkSettings) { let proxySettings = NEProxySettings() proxySettings.httpEnabled = true proxySettings.httpServer = NEProxyServer(address: "127.0.0.1", port: 9000) proxySettings.httpsEnabled = true proxySettings.httpsServer = NEProxyServer(address: "127.0.0.1", port: 9000) proxySettings.matchDomains = [""] settings.proxySettings = proxySettings } When matchDomains is nil or not set, HTTP/S traffic does not reach the local proxy in this configuration. Setting matchDomains = [""] makes it work correctly. The matchDomains documentation states: "If the destination host name of a HTTP connection shares a suffix with one of these strings then the proxy settings will be used." An empty string is a suffix of every string, so [""] matching all hostnames follows from that definition. But this isn't explicitly documented. Questions: Is matchDomains = [""] a supported and stable way to apply proxy settings to all HTTP/S traffic when no IP routes are claimed, or is this an unintended side-effect? Why does matchDomains = nil not apply the proxy globally in this configuration? The documentation doesn't describe its behaviour relative to IP routing. NEDNSSettings.matchDomains explicitly documents an empty string as matching all domains — is the same semantics intended for NEProxySettings.matchDomains?