---
title: "How to change switch uplink speed - Mellanox ONYX OS switches"
slug: "how-to-change-switch-uplink-speed-mellanox-onyx-os-switches"
description: "How to change switch uplink speed - Mellanox ONYX OS switches"
updated: 2026-10-27T19:37:32Z
published: 2026-10-28T18:36:57Z
canonical: "docs.vastdata.com/how-to-change-switch-uplink-speed-mellanox-onyx-os-switches"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How to change switch uplink speed - Mellanox ONYX OS switches

## Summary

By default, the uplink ports for Mellanox ONYX-OS based VAST NVMe Fabric switches (ie. Mellanox SN2100 or SN2700 or SN4600) are set to 100Gbps. Sometimes there are only 40Gbps uplinks at the customer data center, so we need to configure the uplink speed to be 40Gbps. Here are the steps to do so:

## Procedure

1. Login the master Mellanox switch by ssh admin@MELLONIX_SW_IP
2. Assuming we use port 15 and 16 as uplinks, run the following commands

```plaintext
switch-a73786 [labsw1: ] > en
switch-a73786 [labsw1: ] # configure t
switch-a73786 [labsw1: ] (config) # interface ethernet 1/15-1/16
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # no mlag-channel-group
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # shutdown
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # speed 40G
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # no shutdown
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # mlag-channel-group 1 mode active
switch-a73786 [labsw1: ] (config interface ethernet 1/15-1/16) # exit
switch-a73786 [labsw1: ] (config) # exit
switch-a73786 [labsw1: ] # configure write
```
3. Do the same on the secondary Mellanox switch
4. Remember save the configuration with `configure write` command