Seeing several thousand retransmits every 10 sec. via iperf3 on TCP traffic through a proprietary network bridge device

Seeing several thousand retransmits every 10 sec. via iperf3 on TCP traffic through a proprietary network bridge device

If you are experiencing issues with your network connection and notice a high number of retransmits, this article will help you understand the problem and provide some possible solutions.

What are retransmits?

Retransmits occur when data packets are lost or corrupted during transmission and need to be resent. They can significantly impact network performance and cause delays or disruptions in your connection.

Identifying retransmits using iperf3

Iperf3 is a popular network testing tool that can help diagnose network issues. By running iperf3 tests on your network, you can measure the performance and identify any retransmits occurring during the test.

To check for retransmits using iperf3, follow these steps:

1. Install iperf3 on your computer.
2. Open a command prompt or terminal.
3. Type the following command to start the iperf3 server: iperf3 -s
4. On another computer or device, run the iperf3 client command to connect to the server: iperf3 -c [server IP]
5. Let the test run for a few minutes and observe the retransmit count.

Possible causes of retransmits

Seeing several thousand retransmits every 10 seconds indicates a significant problem in your network. Here are some potential causes:

• Network congestion: If your network is overloaded with traffic, it can lead to packet loss and retransmits. Consider prioritizing critical traffic or upgrading your network infrastructure.
• Network interference: External factors like electromagnetic interference or physical obstacles can cause data corruption and retransmits. Ensure there are no sources of interference near your network devices.
• Hardware or software issues: Faulty network equipment or outdated drivers can contribute to retransmits. Make sure your devices are running the latest firmware and drivers.
• Configuration problems: Incorrect network settings or misconfigured devices can lead to retransmits. Double-check your network configuration and consult the device manuals or support resources.

Possible solutions

Here are some steps you can take to address retransmit issues:

• Optimize network traffic: Prioritize critical traffic and consider implementing Quality of Service (QoS) to ensure important data gets priority.
• Check network hardware: Verify that all network devices, including routers, switches, and cables, are functioning correctly. Replace any faulty hardware if necessary.
• Update firmware and drivers: Visit the manufacturer's website for your network devices and download the latest firmware and driver updates. Apply them following the provided instructions.
• Review network configuration: Double-check your network settings, including IP addresses, subnet masks, and gateway configurations. Ensure they match the recommended settings for your network.

If the problem persists after trying these solutions, it may be helpful to contact your network administrator or seek further assistance from a professional.

References