OpenWrt Version and Device Information

Oct 13, 2025 by wbrum.org 43 views

Introduction

In this article, we will be discussing a regression issue that affects the link speed of LAN ports on certain devices after upgrading to a specific version of OpenWrt. The issue is characterized by a maximum link speed of 100MBps, which is significantly lower than the expected speed of 1000MBps. We will delve into the details of the issue, provide steps to reproduce it, and explore possible solutions.

Describe the Bug

After upgrading from 23.05.5 to 24.10.10, LAN ports are stuck on 100MBps maximum. This regression issue affects the Netgear Nighthawk X4S R7800 device, which is running OpenWrt version r28427-6df0e3d02a, based on the 24.10.0 release.

OpenWrt Version and Device Information

OpenWrt version: r28427-6df0e3d02a
OpenWrt release: 24.10.0
OpenWrt target/subtarget: ipq806x/generic
Device: Netgear Nighthawk X4S R7800
Image kind: Official downloaded image

Steps to Reproduce

To reproduce this issue, follow these steps:

Upgrade to 24.10.10
Check the max speed via ethtool

Actual Behaviour

The actual behaviour of the device after upgrading to 24.10.10 is as follows:

Install and run ethtool to verify the speed
Example output from ethtool:

root@OpenWrt:~# ethtool lan4
Settings for lan4:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
        Link partner advertised pause frame use: Symmetric Receive-only
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: d
        Wake-on: d
        Link detected: yes

Expected Behaviour

The expected behaviour of the device is as follows:

Client has a maximum speed of 2.5GBps
Router itself should have a link speed of 1000MBps
Speed tests show a maximum of 98-99MBps

Additional Info

Not a cable issue as speeds return after downgrading
IPv6 disabled, EEE disabled on both the client and router, all power saving methods disabled on the client machine, Windows 11, both devices rebooted

Diffconfig

Terms

[x] I am reporting an issue for OpenWrt, not an unsupported fork.

Conclusion

Introduction

In our previous article, we discussed a regression issue that affects the link speed of LAN ports on certain devices after upgrading to a specific version of OpenWrt. In this article, we will provide a Q&A section to address some of the common questions and concerns related to this issue.

Q: What is the root cause of the LAN port link speed regression issue?

A: The root cause of the issue is not yet known, but it is believed to be related to a change in the OpenWrt codebase. The issue is specific to the 24.10.10 release and does not affect earlier versions of OpenWrt.

Q: Which devices are affected by the LAN port link speed regression issue?

A: The issue affects the Netgear Nighthawk X4S R7800 device, which is running OpenWrt version r28427-6df0e3d02a, based on the 24.10.0 release. However, it is possible that other devices may also be affected by this issue.

Q: How can I reproduce the LAN port link speed regression issue?

A: To reproduce the issue, follow these steps:

Upgrade to 24.10.10
Check the max speed via ethtool

Q: What are the symptoms of the LAN port link speed regression issue?

A: The symptoms of the issue include:

Maximum link speed of 100MBps
Speed tests show a maximum of 98-99MBps
Client has a maximum speed of 2.5GBps

Q: How can I troubleshoot the LAN port link speed regression issue?

A: To troubleshoot the issue, follow these steps:

Check the ethtool output to verify the link speed
Disable IPv6 and EEE on both the client and router
Disable all power saving methods on the client machine
Reboot both devices

Q: Is the LAN port link speed regression issue related to a cable issue?

A: No, the issue is not related to a cable issue. Speeds return to normal after downgrading to an earlier version of OpenWrt.

Q: Can I downgrade to an earlier version of OpenWrt to resolve the issue?

A: Yes, downgrading to an earlier version of OpenWrt, such as 23.05.5, can resolve the issue.

Q: Is the LAN port link speed regression issue specific to the Netgear Nighthawk X4S R7800 device?

A: No, the issue may affect other devices as well. However, it is specific to the 24.10.10 release.

Q: How can I stay up-to-date with the latest information on the LAN port link speed regression issue?

A: You can stay up-to-date with the latest information on the issue by following the OpenWrt forums and bug tracker.

Conclusion

In conclusion, the LAN port link speed regression issue after upgrading to 24.10.10 is a significant problem that affects the performance of the device. We hope that this Q&A article has provided helpful information and answers to some of the common questions and concerns related to this issue.