Background:

 

This guide offers a comprehensive troubleshooting guide on speed issues with the Omada switch.

 

This Article Applies to:

 

All TP-Link(Omada) switches.

 

Common Reasons and Steps to Fix:

 

1.  NIC/Port Limitations:

The NIC(Network Interface Card) of your motherboard or computer, the port itself doesn't support Gigabit/10 Gigabit speeds.

 

Solution: Verify that your NIC (Network Interface Card) and router ports support Gigabit/10 Gigabit speeds. Upgrade hardware if necessary. Check device specs and models, and update the firmware your vendor provides.

2. Cable Issues:

Bent cables, poor quality cables, or cables with insufficient category (e.g., below Cat5e) can affect speed.
Bent can make the wires go bad or create a loose connection, which is commonly ignored. 

Solution: It matters in regular troubleshooting to always try a different cable. A 3ft cable is recommended in both speed and PoE troubleshooting. 

Inspect cables for bends or damage. Use high-quality cables (Cat5e or higher). Replace any suspect cables.

 

3. Switch Incapability

In a large network, if you cascade the switches, you have to make sure each switch in this cascade can support 1Gbps or 10Gbps. If a single switch hardware is only 100Mbps, your whole network will be dragged to this bottom line of 100Mbps speed. 

 

Solution: Consider upgrading the low-end switch to 1G or 10Gbps models. This will guarantee the cascade is properly set up and the link speed is not determined by this weak switch. 

 

4. Inaccurate Speed Test Method:

Speed test from the Internet only reflects your computer to the router, to the ISP, and in the end to their speed test server. The switch and router are only parts of this whole transmission, and based on the NAT throughput you can find in the datasheet, it rarely causes a problem.

 

Solution: Use multiple speed test websites/applications and compare the results. 

 

Determine if you have the proper setup in your network. Regular setup would be: Server---ISP---Modem/Router---Switch---PC. 

If you want to test whether your whole network speed was accurate without ISP interference, you are supposed to connect an iperf server on the WAN with a static IP like 192.168.20.100 and connect another computer to the LAN port as an iperf client. Then run the test. This will test the whole setup speed integrity, like the regular setup mentioned above. 

 

If you simply want to verify the local link from PC A to PC B over a switch, PC A---Switch---PC B, make sure you use iperf as mentioned. Both PCs should be getting the same IP under the same subnet. Test the transmission from A to B, and this will verify if your switch is defective or not. 

 

5. Computer Hardware Bottleneck:

This one rarely makes trouble, but you cannot ignore it if it is 10G or you are using this computer as a mini-server. 

The computer's CPU, memory, or hard drive read/write speeds can become bottlenecks, especially during large data transfers. 

Commonly, this happens with the local file transfer, where you see a low speed in retrieving the files from the NAS or mini-server.

Solution: Close unnecessary applications. Ensure your computer meets the minimum system requirements for high-speed internet. 

If you are on a motherboard with a 1Gbps port and an HDD marked as 6Gbps for transfer. If you wish to get more than 500MB/s transfer speed when you get a single large video file, consider upgrading the CPU, RAM, or storage (SSD) of your NAS or mini-server.

Under the same setup, if you are getting multiple small unzipped files, but you are not getting high speed, you should consider zipping them before transferring.

 

Note that this has nothing to do with the switch's performance. In small and scattered file transfers, the bottleneck is the hard drive and the CPU performance.

 

As for the regular PC to test the Internet, you don't have to worry too much. 

 

6. ISP Line Issues:

The operator's line failures, maintenance, or congestion can cause speed reductions.
Solution: Simply contact your ISP (Internet Service Provider) to report the issue. Inquire about outages or maintenance in your area.

7. ISP Bandwidth Limitations:

Even if you purchased a high-bandwidth plan, the ISP may have insufficient actual bandwidth or may throttle speeds during peak hours. 

ISP does not care about your line stability as long as it works most of the time, and you get the proper speed when they do a field speed test. And all your neighbors' fiber lines aggregate to the same optical terminal. And this hardware has its performance limits. 

Unless you purchase a special dedicated line ,in which the terminal serves you separately. Or you will face problems during the peak hours.

Solution: Verify your subscribed bandwidth with your ISP. If you're not getting the advertised speeds, contact them to investigate the terminal(server).

 

8. Speed Test Server/peer Bandwidth Limitations:

The speed test server's bandwidth is insufficient to provide adequate download/upload speeds, as most servers are not dedicated speed test servers. 

(Some)Speed test servers usually require volunteer users to share their servers for testing. 

As it is voluntary or paid minimally, the owner may not maintain the high speed or server health. Their node(server) can be considered a bad node.

Solution: Try different speed test servers. Or manually choose the server that has lower latency tforyou. Some servers may be overloaded or have limited bandwidth.

9. Server Performance Bottleneck:

Same reason above.

Solution: Same as above - try different speed test servers.

10. Server Geographic Location:

Being too far from the speed test server can increase latency and reduce speed. It is recommended to use the speed test tools and server nodes provided by the ISP.
 

Solution: Use speed test servers that are geographically closer to you. 

Consider setting a proper DNS server on your router. The switch is supposed to use the auto-assigned DNS server from the router. Or a computer during the test. Use a reliable DNS server (e.g., Google DNS: 8.8.8.8 and 8.8.4.4, or Cloudflare DNS: 1.1.1.1 and 1.0.0.1). Clear your DNS cache.

Prioritize using the speed test tools and server nodes provided by the ISP, as most ISPs offer their servers in your region to test when they finish your first installation. You are asked by your ISP to make sure the speed is agreed upon in the service. 

11. Firewall/Security Software:

Firewall or antivirus software may be performing traffic control, which can limit network speed.

Solution: Check your firewall and security software settings to ensure they are not blocking or limiting network traffic. Temporarily disable them to see if it improves speed (but remember to re-enable them afterward).

12. Background Programs Consuming Bandwidth:

Background programs (e.g., P2P downloads, cloud synchronization) may consume a large amount of bandwidth.

Solution: Close unnecessary background programs that may be using bandwidth (e.g., file sharing, cloud syncing).

 

Note:

 

Update Log:

 

Jun 10th, 2025:

Release of this article.

 

Recommended Threads:

 

How to Troubleshoot Slow Speed Test Results on Omada Router

How to configure DNS Proxy on the Omada Gateway

How to Disable NAT in Controller Mode and Verify its Status

 

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