Networking down / SFP+ DAC Cable

I received my fully built HL15 with SFP ports for the NIC. My switch is a USW-24-POE. Port 25 is an SFP coming from my OPNSense firewall to give internet to the switch. Port 26 is coming in from the HL15. I purchased this SFP+ DAC Cable from Amazon. In the UniFi controller I have tried setting Port 26 to “Auto”, to “Manual” with “Automatically Negotiate” and “1Gbps FDX”. No matter what settings I have in UniFi the remains gray “Disconnected”. On the HL15 with Rocky Linux I have set the Link negotiation to “Ignore”, “Automatic” and “Manual” with “1 Gb/s” and duplex full.

I have tried every possible combination between the switch and HL15 and cannot get a network connection nor internet to the HL15.

Any recommendations on what to try next within the switch/hl15 settings? Even though the description for the cable states it should work, if you think it’s the cable, what cable would you recommend?

I understand going from a 1GB SFP to a 10GB SFP+ can be an issue, which is why I changed the speeds in the settings. Anything help would be appreciated.

I’m not an expert, but I would have chosen an SFP cable rather than an SFP+ cable. I think it’s more likely for an SFP transceiver to work in an SFP+ port than an SFP+ transceiver to work in an SFP port.

Hello and welcome @matthammond! I actually don’t think this is cable is compatible with your setup. I see this note in the description on Amazon.

  • Note:VANDESAIL DAC cables are not compatible for use with devices from Intel, for HP, and for Brocade.

The SFP+ ports on the Supermicro X11SPH-nCTPF motherboard use an Intel Chipset.

I’m using 10GTek cables with my Unifi equipment and HL15. Looks like you can get them for about the same price as the one you listed. I’ve also had good luck taking advantage on “Used - Like New” options for this cable.

Amazon.com: [Blue] Colored 10G SFP+ DAC Cable - Twinax SFP Cable for Cisco SFP-H10GB-CU1.5M, Ubiquiti UniFi, D-Link, Supermicro, Netgear, Mikrotik, Fortinet, 1.5-Meter(4.92ft) : Electronics

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Sorry - just realized that you are also going from SFP on the switch to SFP+ on the on the HL15. The 10GTek cable has a diagram showing this isn’t supported either with their cables. Gotta rethink this.

Just ordered the cable you suggested with the link. I will be heading out for work before it comes in but will be sure to post back here next week with updates. Thank you.

Update…saw your second post just in time and cancelled the order.

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would this work you think Unifi 10G Direct Attach Cable

Good to hear and sorry about that. I think the solution is to buy a SFP cable and not a SFP+ cable as what was also suggested by @DigitalGarden. I found this on SFP vs. SFP+ vs. QSFP: Key Differences

Is SFP backward compatible with SFP+?
SFP+ ports are typically backward compatible with SFP modules. This means you can insert an SFP module into an SFP+ port, and it will operate at the SFP’s rated speed (1 Gbps). However, inserting an SFP+ module into an SFP port will not work since SFP ports do not support the higher data rates that SFP+ modules deliver.

I’d still go with 10GTek. I’ve never had an issue with them. Probably look around some more but here’s one I found quickly on Amazon.

Amazon.com: 10Gtek 1.25G SFP DAC Twinax Cable - Gigabit Passive Direct Attach Copper Twinax SFP Cable for Cisco SFP-1GBASE-CU2M, Ubiquiti UniFi, Fortinet, Netgear, TP-Link and More, 2-Meter(6.6ft) : Electronics

I’ll go ahead and grab one of these you just linked Amazon.com: 10Gtek 1.25G SFP DAC Twinax Cable - Gigabit Passive Direct Attach Copper Twinax SFP Cable for Cisco SFP-1GBASE-CU2M, Ubiquiti UniFi, Fortinet, Netgear, TP-Link and More, 2-Meter(6.6ft) : Electronics. Thank you @DigitalGarden and @rymandle05

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Great - hopefully that works out for you. There are some hacks you can also try if you feel up to it. I recently did an EEPROM change on some Intel X520-DA2 cards to allow unsupported SFP+ transceivers. It’s on the advanced side but worked for me. I don’t know if it’ll work on the integrated X722 chipset on the HL15. It wasn’t something I needed to do for the 10GTek SFP+ DAC’s to work in my setup.

There’s also an ixgbe driver option that can be used in Linux by adding options ixgbe allow_unsupported_sfp=1 to a file in the folder /etc/modprobe.d.

A quick guide: Enabling unsupported SFP+ transceivers on the Intel X520/Dell R720 : r/homelab

If the problem is on the Unifi side this won’t help you out any other than to help rule out the issue being with the HL15.

UPDATE: I had some more spare time and it looks like the X722 chipset uses the i40e driver which lacks this option. Unsupported SFP+ transceivers on Intel NIC - General questions - VyOS Forums

Do you get your SFP cable from Amazon? Did it take care of your problem?

The cable did come in; however, I am out of town. I left last Wednesday for work and the cable delivered that day. I will be back from this work trip this Thursday and will be able to test. I’ll be sure to post my results.

Sweet! Looking forward to hearing the results.

So tried the new cable and not working. Anytime I boot up the HL15 I get notified that the network driver is unhealthy. When I go to the bios and inspect it states the SFP plugged in is not recognized. I’ve tried booting then plugging in and using nmtui in the terminal to activate the port. So maybe it’s something else going on. All I’ve done since receiving the fully built HL15 from 45 Drives was install 15 hard drives and that was it. Haven’t messed with any other hardware or software settings (other than changing default password and setting a sudo password).

Huh. Well the fact that you get something even an unhealthy warning is better than nothing. Was the happening before with the other cable?

What do you see if you run ethtool against the interface? I assume you get the same result with either SFP port?

When I run ethtool the part that stands out is Link detected: no

I plugged my laptop directly into the SFP port of the USW-24 and works fine. So, I’ve at least eliminated that the issue is the switch. I can’t imagine it to be the HL15 as I would assume it was tested prior to shipping since it was a fully built server. I have tried 4 different DAC now and also bought 4 different SFP modules and tried running Cat 6 cable to the modules and nothing works on the HL15.

Bummer. What does ethtool -i have for a firmware version? My next suggestion would be see if there’s a firmware update for the nic.

driver 140e
version 4.18.0-477.27.1.el8_8.x86_64
firmware 4.11 0x800001da4 1.2527.0

I have a TPLink SFP to Ethernet converter box too and used the DAC cable from the switch to the converter to my laptop, to another linux machine (laptop and other machine are RJ45) and everything works other than when plugged into this HL15 I just got.

This post suggest me there’s a version 5.5 available.

Best would be to open a ticket with Supermicro to see if they can supply the firmware since is a LoM implementation. You might be able to get it from Intel too, but if it’s not that then I suspect you might need to RMA the board.

This makes me believe 45HomeLab did not actually test my server after they build it before shipping it to me. And I say this because I bought a WorkStation from them at the same time and both shipped together. The WorkStation was purchased with a GPU. In the box was the signed paperwork from the person who built and tested it; however, there was no GPU in the computer at all. They had to mail me one. So it wouldn’t surprise me if I have bad NICs and all that was done was rocky Linux was installed and then the thing shipped.
I’ll see about updating the drivers from a usb and if not then I’ll contact SuperMicro.

FYI - I just got home and was able to check my HL15. It’s running the same firmware you have.

root@Truenas-HL15# ethtool -i eno1 
driver: i40e
version: 6.6.44-production+truenas
firmware-version: 4.11 0x80001da4 1.2527.0
expansion-rom-version: 
bus-info: 0000:67:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes

The only difference here is I’m running TrueNAS. I’m really stumped as to what else could be wrong other than faulty hardware. Have you tried booting off an USB drive into a newer live distro like Ubuntu 22.04 or 24.04? That would help build or rule out the case for bad hardware.