System.Net.NetworkInformation.TcpState public enum TcpState Documentation Closed = 1 CloseWait = 8 Closing = 9 DeleteTcb = 12 Established = 5 FinWait1 = 6 FinWait2 = 7 LastAck = 10 Listen = 2 SynReceived = 4 SynSent = 3 TimeWait = 11 Unknown = 0