Route10 SFP+ DAC issue

I noticed a couple other people experienced the same issue in the Route10 FAQs thread, so I figured I’d create a separate thread with my troubleshooting info in case it makes the issue easier to track and resolve.

I’m trying to use both SFP+ ports to connect to switches on my network. One switch is right next to the Route10 and the other is about 8’ away.

Troubleshooting steps so far:

  • Port WAN2 mode changed from WAN to Standard on Route10
  • Connect .5-meter 10Gtek DAC cable between Route10 LAN4 and near switch. Connects right away and works as expected.
  • Connect .5-meter 10Gtek DAC cable between WAN2 and near switch. Connects right away and works as expected.
  • Connect 3-meter 10Gtek DAC cable between either WAN2 or LAN4 port and the remote switch (~8’ away) and the remote switch will detect the connection, try to negotiate and fail. No indication that it’s detected on the Route10 when plugged into either LAN4 or WAN2.
  • Connect 3-meter 10Gtek DAC cable between both switches and they connect right away and work as expected.

The 10Gtek cable part number is CAB-10GSFP-P3M. This is 10GBASE-CU SFP+ Cable 3-Meter, Passive. I have two of these cables and the results are the same using either one. No troubles at all with the .5-meter 10Gtek cable.

Happy to do any additional troubleshooting that may help.

Thanks!

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I’m playing around with a similar issue, though it does seem to be working for me and the port is showing 10G. For the Route10, if you go to the interface of one of the SFPs, does the Speed show Default?

If so, what if you set it to Auto or force 1Gbps

It was set to Default. I just tried setting the port to Auto and forcing 1Gbps. The behavior was the same for both settings.

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I know this may sound derivative, but after forcing it to 1Gbps, did you re-seat the SFP connectors?

It’s possible that SFP modules on the DAC aren’t supported, but in replicating this similar issue with a Protectli DAC - setting the port speed to 1Gbps and reseating gave me a link. Then setting it to Auto it renegotiated at 10G.

It’s a good question. I did reseat the connector after every mode change when I tested because the just doing the mode change wasn’t enough for the switch to try and renegotiate.

I’m willing to bet the modules are the same on my .5 meter cable and the 3 meter cable since they are both from the same manufacturer and are under 30 meters, which is the shortest distance modules tend to be rated for.

While a fix to make this cable work would be fantastic, a list of supported DAC cable make and models would be a good start. DAC cables are a more cost effective option than getting 2 10GBase-T modules and using CAT6 cable or picking up 2 10GBase-SR modules and a fiber cable.

Are the port speed settings the same on both the route10 port and switch? Have you tried using both on auto instead of default? What happens if you set a link speed for both devices instead of auto negotiate does it connect then?

The switch I’m trying to connect with the DAC cable is a Netgear XS512EM. Ports 11 & 12 are hybrid ports with an SFP+ and RJ45 port for each. The only options on the switch for port speed configuration are Auto (default), Disable and 100Mbps Full. No option to force a speed compatible with the DAC.

In my testing, I’ve had both sides set as auto and also tried to force the Route10 to 1Gbps with the switch still on auto.

I can connect to an RJ45 port, but then am limited to 2.5Gbps. Picking up a 10Base-T SFP+ module is also an option, but there isn’t a list of compatible modules (or DAC cables) yet, so I’d be rolling the dice on compatibility.

I’m willing to bet it’s because it’s only SFP not SFP+ on your switch. Your DAC may not be negotiating down to 1GB.

I double checked the manual for the router and it says they are SFP+ ports supporting 1Gbps and 10Gbps speeds.

The port itself does yes but your module might not. Seems like you are using a SFP+ module and your switch is only SFP. Your module might not negotiate to SFP.

The cable I’m using is SFP+. Here is a link to the cable from Amazon where I bought it.

Here’s a link to the manufacturer’s (10Gtek) product page that also lists the cable as SFP+. The specific product number for the cable I’m using is CAB-10GSFP-P3M.

And here’s the data sheet which also notes SFP+.

The switch and the cable are both SFP+. If I connect the exact same cable to the other switch which is also SFP+ , it immediately negotiates at 10Gbps and works as expected.

If you find a module that isn’t compatible, we intend to improve compatibility through firmware updates based on user feedback.

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Have you tried an optical Dac ? OH I should try this too, I have a like 75’ one I could try. Whips out cable, Reporting back today !

Here you go, cable tested and working with a 10m Optical DAC.

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I only had the two 3-meter copper DACs which didn’t work. Good to see the AOC working. Ended up picking up a 10Base-T module, which is working for me now. Will pick up an AOC for this soon and repurpose the 10Base-T module for another switch where I have RJ45 wall jacks.

This worked for me, thanks for all the good information:
NOTE: At the time I ordered only the 2 meter was available.

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The optical DAC’s are the best ! IMO