---
title: iff_protocol
framework: Kernel
role: symbol
role_heading: Instance Property
platforms: [macOS 10.6+]
path: kernel/iff_filter/1589949-iff_protocol
---

# iff_protocol

The protocol of the packets this filter is interested in. If you specify zero, packets from all protocols will be passed to the filter.

## Declaration

```occ
protocol_family_t iff_protocol;
```

## See Also

### Fields

- [iff_cookie](kernel/iff_filter/1589954-iff_cookie.md)
- [iff_name](kernel/iff_filter/1589945-iff_name.md)
- [iff_input](kernel/iff_filter/1589946-iff_input.md)
- [iff_output](kernel/iff_filter/1589942-iff_output.md)
- [iff_event](kernel/iff_filter/1589952-iff_event.md)
- [iff_ioctl](kernel/iff_filter/1589948-iff_ioctl.md)
- [iff_detached](kernel/iff_filter/1589944-iff_detached.md)