---
title: ecn_fallback_synrst
framework: Kernel
role: symbol
role_heading: Instance Property
platforms: [macOS 13.0+]
path: kernel/if_tcp_ecn_stat/3944030-ecn_fallback_synrst
---

# ecn_fallback_synrst

## Declaration

```occ
u_int64_t ecn_fallback_synrst;
```