### Understand the alert

This alert is triggered when a significant number of inbound dropped packets are detected on the network interface of a Virtual Machine (VM) over the last 10 minutes. It indicates a potential issue with the VM's network connectivity or performance.

### What does inbound packets dropped mean?

Inbound dropped packets refer to packets that are received by a network interface but discarded before they are processed by the VM. This can occur for various reasons, such as network congestion, errors in packet content, or insufficient resources to handle the incoming data.

### Troubleshoot the alert

1. **Check for network congestion**: High network usage can lead to packet drops when the network is saturated, or bandwidth is insufficient to handle the incoming traffic. Monitor the overall network usage in your environment to identify if this is the cause.

2. **Inspect network errors**: Errors in packet content, such as checksum errors or framing errors, can result in dropped packets. Examine logs at the hypervisor and VM level for any indication of network errors.

3. **Check resource usage within the VM**: Inspect CPU, memory, and disk usage within the VM. High resource utilization can lead to degraded network performance and dropped packets.

4. **Verify VM network configuration**: Ensure that the VM's network configuration, such as its IP address, subnet mask, and default gateway, are correctly set. Misconfigured network settings can cause network issues, including higher rates of dropped packets.

5. **Check for faulty network hardware**: Damaged or malfunctioning network hardware, such as network interface cards (NICs) or cables, can result in dropped packets. Check the hardware components involved in the VM's network connection and replace any faulty components.

6. **Evaluate hypervisor performance and configuration**: The performance of the hypervisor hosting the VM can also impact network performance. Ensure the hypervisor has adequate resources and is configured correctly for optimal VM network performance.

### Useful resources

1. [vSphere Networking Guide](https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.networking.doc/GUID-32DA33D2-7B68-471B-AF7F-0AE5456070EC.html)
2. [vSphere Troubleshooting Guide](https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.troubleshooting.doc/GUID-12989131-47E7-4005-B940-5BA5F5C089CF.html)
3. [VM Network Troubleshooting Best Practices](https://www.vmwareblog.org/troubleshooting-vm-network-performance-part-1/)