| 1 | ### Understand the alert |
| 2 | |
| 3 | This alert is triggered when the number of outbound discarded packets for a network interface on a Windows system reaches or exceeds 5 in the last 10 minutes. Discarded packets indicate network problems or misconfigurations and can lead to decreased performance, slow connections and communication errors. |
| 4 | |
| 5 | ### What are outbound discarded packets? |
| 6 | |
| 7 | Outbound discarded packets are network packets that were not sent successfully from a Windows host to the intended destination. This might be due to various reasons such as buffer overflows, device driver errors, or network congestion. Discarded packets may result in retransmissions, which could cause increased latencies and reduced network throughput. |
| 8 | |
| 9 | ### Troubleshoot the alert |
| 10 | |
| 11 | 1. Check network performance statistics |
| 12 | |
| 13 | Use the built-in `netstat` command to display network statistics: |
| 14 | ``` |
| 15 | netstat -s |
| 16 | ``` |
| 17 | |
| 18 | Look for errors or high discard rates, which may indicate network problems. |
| 19 | |
| 20 | 2. Monitor network interface performance |
| 21 | |
| 22 | Use the `Performance Monitor` tool in Windows to monitor the network interface for issues. Look for counters related to discarded packets, such as `Packets Outbound Errors`, `Packets Received Errors`, and `Packets Sent/sec`. |
| 23 | |
| 24 | 3. Identify if there are specific applications with high discard rates |
| 25 | |
| 26 | Use the `Resource Monitor` tool in Windows to check which applications are consuming the most network resources and identify if any specific application is causing high discard rates. |
| 27 | |
| 28 | 4. Check for errors, warnings, or unusual events in the Windows Event Viewer |
| 29 | |
| 30 | Open the `Event Viewer` in Windows and browse through the System and Application logs for any network-related events. Look for errors or warnings that could be related to network configurations, device driver problems, or application-specific issues. |
| 31 | |
| 32 | 5. Update or reinstall network drivers |
| 33 | |
| 34 | Outdated or corrupt network drivers can cause discarded packets. Ensure your network drivers are up to date and, if necessary, reinstall the drivers. |
| 35 | |
| 36 | 6. Check network components and configurations |
| 37 | |
| 38 | Inspect network cables, switches, and routers for any physical damage or malfunction. Check the network settings on the Windows host to ensure they are correctly configured, including DNS, gateway, and subnet mask. |
| 39 | |
| 40 | 7. Network congestion |
| 41 | |
| 42 | If your network is congested, it can cause an increase in discarded packets. Consider upgrading network equipment or implementing quality of service (QoS) policies to prioritize and manage network traffic more effectively. |
| 43 | |
| 44 | ### Useful resources |
| 45 | |
| 46 | 1. [Using Performance Monitor to monitor network performance](https://techcommunity.microsoft.com/t5/ask-the-performance-team/using-perfmon-to-monitor-your-servers-network-performance/ba-p/373944) |
| 47 | 2. [Event Viewer in Windows](https://www.dummies.com/computers/operating-systems/windows-10/how-to-use-event-viewer-in-windows-10/) |