An administrator is researching a problem with virtual desktops hosted on AHV clusters. Users report intermittent issues when viewing video in VDI desktops. The problem exhibits as hung/frozen display frames and problems starting the streaming video. Which network configuration could cause the issue?

The symptoms of frozen frames and failure to start video streams suggest significant packet loss. A common cause for this in an AHV environment is a network misconfiguration between the host and the physical switch. Balance-SLB (Source Load Balancing) on the AHV host balances VM traffic across uplinks based on the VM's MAC address and does not require special switch configuration. However, if the upstream physical switch ports are configured in a Link Aggregation Group (LACP), the switch expects to negotiate using the LACP protocol. Since Balance-SLB does not use LACP, the switch will drop most of the traffic, leading to severe packet loss and the reported video issues.

A. Route based on physical NIC load: This is a general description of Balance-SLB, which, when correctly implemented with a standard switch configuration, does not cause this issue.
B. Route based on IP hash: This is the host-side setting for LACP. While it can cause out-of-order packets, it would not typically cause the severe packet loss described if the switch is also configured for LACP.
D. Active-Backup: This is the simplest and most stable mode. It uses only one active link, making packet loss or reordering from the load-balancing mechanism impossible.

1. Nutanix. (2023). AHV Administration Guide v6.5. Section: "Host Network Management", Subsection: "Load Balancing in a Bond". The guide explains that using balance-slb against a switch configured for LACP (static or dynamic) is an unsupported configuration that will cause connectivity issues.

2. Nutanix. (2022). Nutanix Networking Best Practices. Section: "AHV Networking". This document clarifies the different bond modes and their requirements, highlighting the incompatibility of balance-slb with LACP-configured switch ports, which can result in packet loss.