### Understand the alert

This alert is triggered when the ratio of outbound errors for the network interface of a virtual machine in vSphere is greater than 1 over the last 10 minutes. Network outbound errors can include dropped, discarded, or errored packets that couldn't be transmitted by the network interface.

### What are outbound packet errors?

Outbound packet errors occur when a network interface is unable to transmit packets due to issues like network congestion, hardware problems, or misconfigurations. A high number of outbound packet errors can indicate problems in the network and affect the performance of the virtual machine, resulting in poor application responsiveness and reduced bandwidth.

### Troubleshoot the alert

1. Verify the virtual machine's network configuration.
   - Check virtual machine settings in vSphere to ensure the correct network adapters are assigned and configured properly.
   - Check the virtual machine's guest operating system network configuration for possible errors or misconfigurations.

2. Monitor vSphere network performance counters.
   - Review the network performance counters in vSphere to identify issues or bottlenecks that might be causing the outbound packet errors.

3. Check the physical network.
   - Verify the physical network connections to the virtual machine, including cabling, switches, and routers.
   - Inspect the network hardware to ensure proper functioning and identify faulty hardware.

4. Evaluate network congestion.
   - High network traffic can cause congestion, leading to increased outbound packet errors. Evaluate the network's current usage and identify potential bottlenecks.
   
5. Review vSphere network policies.
   - Check the network policies applied to the virtual machine, such as rate limiting or other traffic shaping policies, that may be causing the increased rate of outbound packet errors.

6. Examine applications and services.
   - Review the applications and services running on the virtual machine to determine if any of them are generating excessive or abnormal network traffic, resulting in outbound packet errors.

### Useful resources

1. [VMware: Troubleshooting Network Performance](https://www.vmware.com/support/ws5/doc/ws_performance_network.html)
2. [vSphere Networking Guide](https://docs.vmware.com/en/VMware-vSphere/7.0/vsphere-esxi-vcenter-server-70-networking-guide.pdf)
3. [VMware: Monitoring Network Performance Using vSphere Web Client](https://kb.vmware.com/s/article/1004099)
