I have the Unifi Dream Machine Pro and a non POE Unifi 24 port switch.  The DMP has (10gb) and the switch has (1gb)    

For now I've just had an ethernet cable connecting them together but I'd like to use a fiber cable because why not.   Both the switch and dream machine pro have 2 SFP connectors and I'm not sure if they are interchangeable (Can use any of them.)   When I connect the fiber cable I get no lights on the ports.  I have unplugged the ethernet cable, restarted and nothing.  Do I have to somehow enable these ports in the management software?   With the fiber cable connected, if I go into the management software and mouse over the port its dark (not lit up) but I can it sees the serial number of the connectors and some other data.   I just can't figure out how to turn them on.

I don't believe the UDM Pro auto-negotiates on the SFP and you will need to set the UDM Pro to 1gb on the SFP port.

Yes I agree, I just don't know how to do it.  

The SFP port on UDM Pro has Autonegotiation so your problem is probably somewhere else.  Bad cable, or wrong Port Profile on the ports, perhaps.

In your controller, go to Devices and click the UDM pro.
Then, click on the SFP port in the port status graphic at the top of the window.
Now, expand the Port Profile Override menu. You can adjust the link speed with the Link Speed dropdown.

Also, check the port profile is set correctly on both the UDM and the USW to allow traffic on your desired VLANS on each of those SFP ports.

Also, the SFP+ port 10 on the UDM pro is preconfigured to work as a Secondary WAN port. Try port 11 first.

Attached File

Thanks, for some reason I can use/find the menu's easier on the iphone or ipad using their app.   Port 10 on the DMP shows as disabled so I'll try port 11 later when I get a chance.   Port 11 on DMP and port 25 and 26 on the switch show auto-negotiate so I'm probably good there.  I'm thinking it could be the cable as I got it from Amazon because on Ubiquiti's website is shows sold out.   The Amazon cable says Ubiquiti compatible but perhaps not.   Here is what I tried.  https://smile.amazon.com/gp/product/B07B6KXLPG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

If everything is right on both devices, you may need to pull apart the pair of connectors at one end or the other and swap them..

With some fiber jumpers/patch cables (many actually) the tx goes in on on one side on one end and and out the same side on the other end...  
So each end's laser are beaming down the same strand and colliding....  
You need the TX from device A to go into the RX on device B. and vise versa...

Just the other night, we were upgrading from a 1G  to a 10G circuit at one of our pops and they could not get the link up I spoke up and said maybe check the fiber positions or polarity for your RX/TX...  
NO, NO, that's not it....  
After watching and listening to them for almost an hour, I said Check the fibers...  No no thats not it...
After another half hour or so, I said, OK, we got folks down and at the risk of stating the obvious, we need to get this link up.
I am going to pull the jumper on one and and swap the RX/TX.  As soon as I did, I saw the link light come on and activity light start blinking away.
I said, Link is up.

Them: Well, what did you do?
Me: I corrected the fiber positions on the RX/TX... Swapped them... As I mentioned, a few times.
Them: You don't have to do that...
Me:  OK, Links Up.
Them: You don't have to do that!!!
Me: I can put it back the other way and take the link down if you prefer....  

You can also check your fiber if you have a meter or Visual Fault Locator, it looks like a Mini0Mag light with a fiber adapter on the end and shines a red LED/Laser down your jumper to see where (which side) it comes out.  Very handy if you mess with fibers much.

Do they think Rx and Tx just swap themselves as needed?

That cable won't work for that.  To run fiber, you need 1G fiber modules.

Eta- that's an 10G SFP+ direct attach copper cable.  The UDM pro can't negotiate SFP+ to SFP over that cable.  A regular 1G SFP DAC may work, but I haven't tried it.  I believe port 12 is a dedicated WAN port.

other things to watch out for, besides the aforementioned crossing the TX/RX...

SFP (small form factor pluggable) modules come in a huge variety of different types.
besides the data rate, the module has to be used with a compatible fiber type, and of course the module at the other end has to be the same type as well.  note, just because the LC connectors engage and lock into place does not make the fiber compatible.  

example, if you are using a 10G SR (short reach) SFP+ which is set up for multimode fiber, you need an identical module for the mate and a length of multimode fiber (MMF) to interconnect them.  if the modules at the two ends differ, or the interconnecting fiber is an incompatible type, the link will not come up.

moar info on fibers
https://community.fs.com/blog/single-mode-cabling-cost-vs-multimode-cabling-cost.html

He's not using a fiber cable yet.  He has a SFP+ DAC.  I went ahead and ordered the same cable he's using to see if it works with my UDMP and USW-16 POE.  I'm fairly confident it won't work, but will be pleasantly surprised if it does.

I ordered the same cable OP linked to, and the link between my UDMP and USW 16 POE is working nicely.  Using port 11 on the UDMP and SFP1 on the USW.  I have both manually set to 1000 Mbps FDX.  I have tried this with the official Unifi DAC and had no luck.  This DAC seems to work fine for now.

My god how I hate this.  It's the first thing I do.  Step 1

ahh, missed that part.  

i will stay in my lane now.  

It's not about staying in your lane.  The OP was a bit misleading, and I don't think they know the difference between fiber and twinax DAC.

Not sure if we'll get an update, but the cable is still humming right along in my setup where I didn't think it would.

Just for testing purposes, OP could open this port in the Profile Overrides section, and change it from Autonegotiation to 1Gbps FDX.

I also wonder if the Twinax DAC is the issue as well. I have used the 10GTek SFP modules off Amazon to connect my Unifi stuff, along with Amazon's multi-mode fiber. Yeah, it costs more ($20 for each of two SFP modules and another $15-20 for 1-2M fiber). But it connects without a hitch.

I fully understand doing SFP "because I can". But if you're just connecting at 1Gbps, it seems like a lot of work for no gain. Now doing 10 Gbps at home "because I can" is a great idea.

Yeah, sorry I don't know squat about Fiber connectors or connections and this isn't a business, just my home network setup.   I eventually did get a chance to try the cable and set the ports manually to 1gbps but I think I did something wrong as the connection was very very slow.  I ended up just reconnecting the cat5e cable as they are really both the same speeds anyway.   Maybe I'll give it a shot again later as I'm watching lots of youtube videos on unifi setups and learning quite a bit.    Thanks all.

I'm sure I know less than most people in this thread.

Anyways, did you reboot your equipment after setting everything and connecting the cable?

I did a SFP 1g connection to not 'waste' one of my 8 poe ports for the uplink.

Pretty sure I did but I did it quick and then said its fubar and reversed everything.  I do want to try it again but probably won't get a chance until next weekend.  If I get it working I'll let everyone know.