X55 Port 2 appears dead

X55 Port 2 appears dead

X55 Port 2 appears dead
X55 Port 2 appears dead
2024-08-13 12:35:54
Model: Deco X55  
Hardware Version: V1
Firmware Version: 1.2.0

I have an X55 as my main unit, with an X50 connected over Ethernet as a secondary unit. This set up was working fine up until a few days ago when I would wake up in the morning to find the X50 falling back to a WiFi backhaul connection. Various attempts at rebooting the devices would fix the issue until today, when no amount of rebooting would help. After rebooting both units, I noticed that the only clients that maintained a connection were (1) WiFi on the main unit and (2) Wired on the main unit (connected on Port 3 to a switch). I swapped the X50's backhaul cable to Port 3 and I observed that the Ethernet backhaul came back online and my wired clients went offline. I then connected the backhaul to the switch and the switch to Port 3, and everything came back up. This really looks like Port 2 on my main unit is dead, but I want to confirm this. Is there any way to test this theory?

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#1
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5 Reply
Re:X55 Port 2 appears dead
2024-08-15 10:29:52

  @subpopculture 

I believe that you already tested adequately, by using, from port 2 of the main Deco, different cables to different devices, none of them working on port 2, each of them working on port 3.

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#2
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Re:X55 Port 2 appears dead
2024-08-16 13:07:55

I did some more testing since posting this, including a factory reset. After the factory reset, it was Port 3 that was not connecting instead of Port 2. This showed me that the issue is likely caused by software, not hardware. I was "fortunate" enough to have had an earlier issue that I raised with TP-Link support. As part of this, they installed a development build firmware on my X55 which allows for shell access to the device. So I connected to the shell and started looking at the bridge interface configuration, having a hunch that the issue is caused by the automatic interface assignments to the WAN and LAN bridges. It turns out this hunch was right. The device has two bridges: br-wan and br-lan. They were configured with eth1.3 and eth1.593 assigned to br-lan, and eth1.2 and eth1.4 assigned to br-wan. After a little trial and error, I figured out that eth1.2 was my ISP uplink interface, so I took eth1.4 out of br-wan and assigned it to br-lan. That "fixed" my "dead" Port 3.

 

root@X55:/# brctl show
bridge name     bridge id               STP enabled     interfaces
br-iptv         8000.000000000000       no
br-lan          7fff.74fece0bc97c       no              ath0
                                                        ath02.1
                                                        ath02.2
                                                        ath1
                                                        ath12.1
                                                        ath12.2
                                                        eth1.3
                                                        eth1.591
br-wan          8000.74fece0bc97d       no              eth1.4
                                                        eth1.2
root@X55:/# brctl delif br-wan eth1.2
root@X55:/# brctl addif br-lan eth1.2
root@X55:/# brctl show
bridge name     bridge id               STP enabled     interfaces
br-iptv         8000.000000000000       no
br-lan          7fff.74fece0bc97c       no              ath0
                                                        ath02.1
                                                        ath02.2
                                                        ath1
                                                        ath12.1
                                                        ath12.2
                                                        eth1.2
                                                        eth1.3
                                                        eth1.591
br-wan          8000.74fece0bc97d       no              eth1.4

 

I am skeptical this will survive a reboot of the device, but I have not tested that yet. I also don't know where in the init scripts or config files I can go to fix this permanently.

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#3
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Re:X55 Port 2 appears dead
2024-08-16 13:16:50

  @subpopculture 

Interesting!

By the way, 591 is the vlan id for the guest network.

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#4
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Re:X55 Port 2 appears dead
2024-08-16 13:35:09

  @yves_b Ah! That clears things up. I wasn't sure why there were 4 interfaces in these two bridges, considering the X55 only has 3 ports. This makes so much more sense now. If the naming assignment is consistent, then it goes from the bottom up.

 

Port 3 is eth1.2

Port 2 is eth1.3

Port 1 is eth1.4

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#5
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Re:X55 Port 2 appears dead
Friday

  @subpopculture Within the last week I purchased 3 Deco X55s. The wifi works great but port 2 on the main router is dead, and port 3 will switch on and off rapidly. I conducted a similar assessment as you. I factory reset the routers and still dead. I contacted TP Link, and new one is going to be on the way.

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#6
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