---
title: IFNET_TSO_IPV4
framework: Kernel
role: symbol
role_heading: Enumeration Case
platforms: [macOS 10.12+]
path: kernel/1644631-anonymous/ifnet_tso_ipv4
---

# IFNET_TSO_IPV4

## Declaration

```occ
IFNET_TSO_IPV4 = 0x00200000
```

## Discussion

Discussion Hardware supports IPv4 TCP Segment Offloading. If the Interface driver sets this flag, TCP will send larger frames (up to 64KB) as one frame to the adapter which will perform the final packetization. The maximum TSO segment supported by the interface can be set with "ifnet_set_tso_mtu". To retreive the real MTU for the TCP connection the function "mbuf_get_tso_requested" is used by the driver. Note that if TSO is active, all the packets will be flagged for TSO, not just large packets.