# TCPX Flags1

> [HTML Version](tcpxflags1.htm)

This first table describes the defined _flags_ bits along with the _opcodes_ that they go with:

| **Symbol** | **Value** | **Opcode** | **Meaning** |
|------|------|------|------|
| TCPXFLG\_BLOCK | \&h00000001 | TCPOP\_ACCEPT, TCPOP\_CONNECT | Establish connection being accepted as blocking.  |
| TCPXFLG\_LISTEN | \&h00000004 | TCPOP\_ACCEPT | Causes TCPX to return with the listening socket in _sockport_ instead of the connection socket, without waiting to accept a connection. |
| TCPXFLG\_ASYNC | \&h00000008 | TCPOP\_ACCEPT | Accept connection on previously opened listening socket. _sockport_ must be the listening socket. |
| TCPXFLG\_ASYNC | \&h00000008 | TCPOP\_CONNECT | Attempt to connect asynchronously. See [Asynchronous Client Connections](asynchronousclientcon.htm.md). |
| TCPXFLG\_KEEPLISTEN | \&h00000010 | TCPOP\_ACCEPT | Combined with TCPXFLG\_ASYNC to keep the listening socket open after accepting the connection. |
| TCPXFLG\_SHUTRD | \&h00000020 | TCPOP\_SHUTDOWN | Shut receiving side only. |
| TCPXFLG\_SHUTWR | \&h00000040 | TCPOP\_SHUTDOWN | Shut sending side only. |
| TCPXFLG\_NODELAY | \&h00000080 | TCPOP\_ACCEPT,<br>TCPOP\_CONNECT | Disable the Nagle delay. |
| TCPXFLG\_LINGER | \&h00000100 | TCPOP\_ACCEPT,<br>TCPOP\_CONNECT | Set the standard TCP option SO\_LINGER to "on". See [Setting The SO\_LINGER Option](settingtheso_lingeroption.htm.md). |
| TCXPXFLG\_TLS | \&h00100000 |  | Support for [TLS/SSL](tlsssl.htm.md). |
| TCPXFLG\_STARTTLS | \&h00200000 | TCPOP\_CONNECT | Support for [STARTTLS](starttls.htm.md). |
| TCPXFLG\_UDP | \&h00400000 |  | UDP mode (with TCPOP\_ACCEPT, TCPOP\_READ)  |


[Hex-Decimal Values](hex-decimalvalues.htm.md)