---
title: tcps_ecn_lost_syn
framework: Kernel
role: symbol
role_heading: Instance Property
platforms: [macOS 12.0+]
path: kernel/tcpstat/3754815-tcps_ecn_lost_syn
---

# tcps_ecn_lost_syn

## Declaration

```occ
u_int32_t tcps_ecn_lost_syn;
```