best practices for esxi networking with vic and mlom adapters on arista switches

Products

• VMware vCenter Server

Issue/Introduction

Users may experience network instability or configuration confusion when deploying ESXi hosts with converged network adapters (VIC) and mLOM adapters connected to Arista leaf switches in an MLAG configuration.

Environment

• VMware ESXi 7.x / 8.x / 9.x
• Cisco VIC / mLOM Adapters
• Arista Leaf Switches (EOS 4.x and higher)

Resolution

When configuring a mix of VIC and mLOM adapters, follow these architectural best practices:

1. Switch Architecture Requirements
   • vSphere Distributed Switch (vDS): Mandatory if implementing Link Aggregation Groups (LAG) or LACP.
   • Standard Switch (vSS): Does not support LACP. Use for simple active/passive teaming for Management traffic.
     
     
2. Link Aggregation Group (LAG/LACP) Configuration
   • Load Balancing Policy: Must be set to Route based on IP hash when using a LAG.
   • Arista MLAG: When Arista switches are in an MLAG pair, configure the ESXi uplinks as a single logical LAG/LACP bundle.
   • LACP Mode: Set physical switch ports to Active LACP.
     
     
3. Traffic Isolation and Trunking
   • Configure physical switch ports in Trunk Mode to handle multiple VLANs (Management, NFS, vMotion).
   • Ensure MTU consistency (e.g., 9000 for Jumbo Frames) across the VIC, vSwitch, and Arista switch fabric.
     
     
4. Download and Documentation
   1. Fixed in release ESXi 8.0 and higher. See Download Broadcom products and software for steps to download.
   2. To speak with a customer representative or a Support Engineer see Contact Support. Scroll to the bottom of the page and click on your respective region.

Additional Information

Host requirements for link aggregation
Example Configuration of LACP
Broadcom Contact Support