| Value | Meaning | 
|---|---|
| defaults0 | Don't enable any particular option  | 
| distribute1 << 0 | Causes incoming connections to be distributed across the thread pool  | 
| disableAutoClose1 << 1 | Disables automatic closing of the connection when the connection callback exits  | 
| reusePort1 << 2 | Enable port reuse on linux kernel version >=3.9, do nothing on other OS Does not affect libasync driver because it is always enabled by libasync.  | 
Flags to control the behavior of listenTCP.