@Dipsy 

yes I agree with you, there is something wrong with SFP WAN/LAN3, my DAC cable is 10/1GB and works great on 1GB SFP ports except SFP WAN/LAN3 on ER8411

I've also got an ER8411 v1 which was connected to an SG2428P via SFP WAN/LAN3 on the ER8411.  Like others, the connection failed after the 1.3.1 firmware update.  This week's 1.3.2 firmware didn't resolve the issue either.

Here's my hardware setup:

• ER8411 v1 (SFP+ LAN/WAN2)  ---- [SFP+ DAC Cables] ---- SG3428X-M2 v1.2  {works fine, no issues with 1.3.1}
• ER8411 v1 (SFP LAN/WAN3) ---- [SFP+ DAC Cables or SFP 1G DAC Cable] ---- SG2428P v1  {connection failed after ER8411 fimware 1.3.1}

I have tried the following cables without success:

• 10GTek 10G SFP+ DAC cable (known working prior to 1.3.1)
• H!Fiber 10G SFP+ DAC cable (known working prior to 1.3.1)
• Generic 10G SFP+ DAC cable (known working prior to 1.3.1)
• 10GTek 1G SFP DAC cable (just purchased to test the "SFP+ DAC cables generally do not work in SFP non-plus ports" comment)

The interesting thing is that the SG3428X-M2 will happily connect to the ER8411's SFP WAN/LAN3 port at 1G. The SG3428X-M2 (SFP+ ports) will also happily connect to any SG2428P (SFP) ports:

• SG3428X-M2 (SFP+ ports 25-28 configured for 1000/FDX) ---- [SFP+ DAC Cables] ---- SG2428P v1 (SFP ports 25-28)   {works just fine}
• ER8411 SFP LAN/WAN3 ---- [SFP+ DAC Cables] ---- SG3428X-M2 v1.20 (SFP ports 25-28 configured for 1000/FDX]   {works just fine}

I only have problems when connecting the ER8411 SFP WAN/LAN3 to any SFP port on the SG2428P (ports 25-28).  Given that Dipsy and MR.S are also experiencing this issue between ER8411 SFP WAN/LAN3 and SG2428P (SFP), I suspect this is a specific incompatibility between these devices after the 1.3.1 firmware update.

Hoping this is useful for TP-Link to find the issue and develop a fix.

Edit: I just remembered I have a generic 2.5G switch with an SFP+ 10G port and I just tested it with the ER8411's SFP LAN/WAN3 port - it syncs at 1 Gbps and works just fine.  I'd love to hear from anyone else in the community to know if anyone has had ER8411 issues with the SFP WAN/LAN3 port with devices OTHER than the SG2428P.  

FYI, here's the firmware versions I'm running:

• ER8411 v1.0 - fw: 1.3.2 (issue originall showed up with fw 1.3.1)
• SG2428P v1.0 - fw: 1.1.15
• SG3428X-M2 v1.20 - fw: 1.20.10

Update - I had a chance to borrow a 10GTek 1000Base-T SFP RJ45 transceiver and when used with the ER8411's SFP LAN/WAN3 port it works just fine.  So far, in all my testing, the SFP LAN/WAN3 port only fails when connected via a passive DAC cable to the SG2428P.  

I've had no issues connecting DAC cables (SFP/1G and SFP+/10G) to the SFP LAN/WAN3 to my SG3428X-M2, or to a generic 2.5G switch.  I'd be curious to see if an AOC (ActiveI Optical Cable) would make a difference, unfortunatley, I dno't have access to any.

No news from TP-Link ?

Are we doomed to use 1.2.3 forever ?

  @Dipsy 

What's the DAC cable you use in this context? 

Specify the diagram of the network and the connection now. 

In simple terms, you upgraded the 1.3.2, and the ports' status will become inactive, disconnected, and unplugged?

  @Clive_A I can't make it clearer than @TA-C #13 reply : https://community.tp-link.com/en/business/forum/topic/824034?replyId=1568248

  @Dipsy 

Dipsy wrote

  @Clive_A I can't make it clearer than @TA-C #13 reply : https://community.tp-link.com/en/business/forum/topic/824034?replyId=1568248

I am asking yours. I am aware of his information, and he seems to fix it based on the update.

If you have a technical problem, you can contact the technical support for help. 

I have a work-around by using an RJ45 ethernet transceiver, but I wouldn't call it a fix.  I've tested with multiple passive DAC cables, and I can't establish connectivity between ER8411 v1 (SFP LAN/WAN3) ---- [SFP+ DAC Cables or SFP 1G DAC Cable] ---- SG2428P v1.

 Same problem here:

• SG2428P v5.30 5.30.8
• ER8411 v1.0 1.3.2

This combination was working fine with a DAC cable on WAN3 to the SG2428P until upgrading the ER8411 to 1.3.2.

Also no link from WAN3 to a Netgear SFP port via DAC cable.

I found the same workaround with a copper SFP.

Looking forward to a fix as this equipment needs to go into production soon.

Edit:

Tested working with:

• TP-Link TXM431-SR fiber SFP+
• D-Link DGS-712 copper transceiver

  @Clive_A Can you confirm this issue is being investigated?