[Netgear R6220 / MT7621] - Port flapping

Installing and Using OpenWrt
1

OpenWrt latest Snapshoot r32277-c2c38469a8

Any ideas how to fix this?, the problem has been occurring for over 1.5 years…

The stable version has been working fine for years, but as soon as I upload a snapshot, the port flips.

[Dec 10, 2025, 12:04:28 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is up
[Dec 10, 2025, 12:04:28 PM GMT+1] kern.info: [   55.267479] mt7530-mdio mdio-bus:1f lan4: Link is Up - 100Mbps/Full - flow control rx/tx
[Dec 10, 2025, 12:04:28 PM GMT+1] kern.info: [   55.267611] br-lan: port 4(lan4) entered blocking state
[Dec 10, 2025, 12:04:28 PM GMT+1] kern.info: [   55.267644] br-lan: port 4(lan4) entered forwarding state
[Dec 10, 2025, 12:04:28 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is down
[Dec 10, 2025, 12:04:28 PM GMT+1] kern.info: [   55.514978] mt7530-mdio mdio-bus:1f lan4: Link is Down
[Dec 10, 2025, 12:04:28 PM GMT+1] kern.info: [   55.515207] br-lan: port 4(lan4) entered disabled state
[Dec 10, 2025, 12:04:32 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is up
[Dec 10, 2025, 12:04:32 PM GMT+1] kern.info: [   59.002424] mt7530-mdio mdio-bus:1f lan4: Link is Up - 100Mbps/Full - flow control rx/tx
[Dec 10, 2025, 12:04:32 PM GMT+1] kern.info: [   59.002556] br-lan: port 4(lan4) entered blocking state
[Dec 10, 2025, 12:04:32 PM GMT+1] kern.info: [   59.002588] br-lan: port 4(lan4) entered forwarding state
[Dec 10, 2025, 12:04:32 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is down
[Dec 10, 2025, 12:04:32 PM GMT+1] kern.info: [   59.190501] mt7530-mdio mdio-bus:1f lan4: Link is Down
[Dec 10, 2025, 12:04:32 PM GMT+1] kern.info: [   59.190755] br-lan: port 4(lan4) entered disabled state
[Dec 10, 2025, 12:04:34 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is up
[Dec 10, 2025, 12:04:34 PM GMT+1] kern.info: [   61.207413] mt7530-mdio mdio-bus:1f lan4: Link is Up - 100Mbps/Full - flow control rx/tx
[Dec 10, 2025, 12:04:34 PM GMT+1] kern.info: [   61.207570] br-lan: port 4(lan4) entered blocking state
[Dec 10, 2025, 12:04:34 PM GMT+1] kern.info: [   61.207619] br-lan: port 4(lan4) entered forwarding state
[Dec 10, 2025, 12:04:38 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is down
[Dec 10, 2025, 12:04:38 PM GMT+1] kern.info: [   64.808490] mt7530-mdio mdio-bus:1f lan4: Link is Down
[Dec 10, 2025, 12:04:38 PM GMT+1] kern.info: [   64.808753] br-lan: port 4(lan4) entered disabled state
[Dec 10, 2025, 12:04:40 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is up
[Dec 10, 2025, 12:04:40 PM GMT+1] kern.info: [   66.892355] mt7530-mdio mdio-bus:1f lan4: Link is Up - 100Mbps/Full - flow control rx/tx
[Dec 10, 2025, 12:04:40 PM GMT+1] kern.info: [   66.892481] br-lan: port 4(lan4) entered blocking state
[Dec 10, 2025, 12:04:40 PM GMT+1] kern.info: [   66.892513] br-lan: port 4(lan4) entered forwarding state
[Dec 10, 2025, 12:04:48 PM GMT+1] kern.info: [   75.046373] mt7530-mdio mdio-bus:1f lan4: Link is Down
[Dec 10, 2025, 12:04:48 PM GMT+1] kern.info: [   75.046686] br-lan: port 4(lan4) entered disabled state
[Dec 10, 2025, 12:04:48 PM GMT+1] daemon.notice: netifd: Network device 'lan4' link is down

Syslog - https://pastebin.com/raw/MwLrV2D9

Kernel - https://pastebin.com/raw/JATu02Bb

2

Bad contact or bad cable?

3

Probably not, because the stable version has been working fine for years, but as soon as I upload a snapshot, the port flips.

4

Certainly cable.

5

I don't think so.

On all other versions of OpenWrt prior to the 24th snapshot, the port works fine and has been stable and error-free for weeks of uptime. The problem only occurs on snapshot versions.

root@AP-Camis2:~# ifconfig lan4lan4      Link encap:Ethernet  HWaddr 9C:3D:CF:C7:1C:70UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1RX packets:27510 errors:0 dropped:0 overruns:0 frame:0TX packets:101597 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:10491949 (10.0 MiB)  TX bytes:121370334 (115.7 MiB)
6

Then what makes you complain? You know dogs, cats, hamsters, kids - all sneak around cables and slightly move them till it breaks after years.

WHat is in other end of cable?

7

I'll check, but I doubt it's the cable's fault. It's a high-quality outdoor cable, but it's only been used in the apartment for a distance of 30 meters. Plus, it's routed in a conduit in the wall, so no one has touched it in about seven years, just like the RJ-45 connectors. As I wrote a moment ago, I reinstalled the stable version and everything is fine now, so I guess it magically fixed itself... :wink:

8

Is it just one port? what happens if you use an other cable in an other port?

What is on the other side?

Is this really an antique router with 100 Mb ports or is the other side some antique equipment with 100 Mb port?

Might need to install ethtool

1 Like
9

I have just installed the latest snapshot, with a PC connected to LAN4. It works as expected. So your problem is elsewhere, bad cable, bad port pins or even hardware failure.