How to Verify Jumbo Frame Configuration for Guest Operating Systems

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides methods to verify Maximum Transmission Unit (MTU) settings, commonly used to check if Jumbo Frames are enabled, for virtual machines running on VMware. User can perform these checks remotely using PowerCLI or directly from within the guest operating system.

Environment

VMware vSphere ESXi 8.x

Resolution

Consider the following options:

Option 1. Using PowerCLI to Fetch Guest OS Jumbo Frame Information

User can use the built-in Invoke-VMScript cmdlet to query the MTU settings remotely without logging into each VM's console.

Prerequisites:

• The VM must be powered on with VMware Tools installed and running.
• One must have valid Guest OS administrator credentials.
• Connectivity on TCP port 902 between PowerCLI machine and the ESXi host.
• Example for Windows Guest:

  Invoke-VMScript -VM "VMName" -GuestCredential (Get-Credential) -ScriptType PowerShell -ScriptText "netsh interface ipv4 show interfaces"

• Example for Linux Guest:
  

  Invoke-VMScript -VM "VMName" -GuestCredential (Get-Credential) -ScriptType Bash -ScriptText "ip link show"

  Note: For further details on scripting and automation, please refer to: Invoke-VMScript

Option 2. Finding Jumbo Frame Information from Inside the Guest OS

If the user is logged directly into the VM via RDP, SSH, or the Web Console, use the following commands:

For Windows (Command Prompt or PowerShell): Run the following command to see a list of all interfaces and their corresponding MTU values: 

netsh interface ipv4 show interfaces

Look for the "MTU" column. A value of 9000 typically indicates Jumbo Frames are enabled.

For Linux (Terminal): Use the ip command (recommended) or ifconfig:

ip link show or ifconfig

In the output, look for the mtu value associated with the active network interface (e.g., eth0 or ens192).

Additional Information

Retrieving VM Subnet Mask and Default Gateway via PowerCLI