Slow upload speed in macOS guests with vmxnet3 network adapter in VMware Fusion
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Slow upload speed in macOS guests with vmxnet3 network adapter in VMware Fusion

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Article ID: 315599

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Updated On:

Products

VMware Desktop Hypervisor

Issue/Introduction

This article provides a workaround to the slow upload speed issue seen in macOS guests like (Ventura/Monterey) with vmxnet3 network adapter.

Symptoms:
macOS Guests created in VMware Fusion with Ethernet adapter configured as vmxnet3 in x86 macbooks showing slow upload speed




Resolution

MacOS guests uses appleā€™s vmxnet3 driver. Currently, there is no resolution.

Workaround:
As a workaround for this issue, VMware recommends to disable TSO in macOS guests.

By default TSO will be on.
sudo sysctl -a | grep net.inet.tcp.tso

Run the below command in macOS guests to turn off TSO
sudo sysctl -w net.inet.tcp.tso=0

To have any sysctl setting stick between restarts:

create a file /etc/sysctl.conf and add a below entry
net.inet.tcp.tso=0