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I am having troubles connecting a 10GB Copper SFP to a M4100-26G-POE
I have connected the SFP to port 26 (the last port on the bottom right) and I have not plugged any cable to ports rj45 (23-26) because it seesm those last ports are shared between the RJ45 and the SFP (so, just in case I have nothing connected there)
I then connect an rj45 cable to the SFP module that is on the switch (port 26) and the other side I connect to my server (that also supports 10GB) I see that it syncs at 10GB however I have no connection at all.
When I connect the same server port to one of the other 1GB port of the switch works perfectly.
I then look at the status of the ports in the switch and it says inactive on port 26, when I look at the logs it does not even track that there was a port state change, nothing. It is has it's nothing there.
I have tried also the sfp module on port 25 and the same result, I have already rebooted the switch a pair of times just in case it needed, but I really don't know what else to do.
The SFP module that I have here is the following (Ipolex for 10GbE 10GBase-T:30m),
Could it be a compatibily issue? I discarded that option because In the description of the SFP module says, its compatible with Netgear switches, and also I see in the status of my server that it syncs at 10Gbit (ethtool eno1np0)
Do I need to do any configuration on my netgear switch? I am lost, don't know what else to do.
Unfortunately no. By rule of thumb, SFP+ slots can take SFP modules (for Gb fiber links for example to connect an SFP and an d SFP+ device), but SFP slots can't take SFP+ modules.
As I said, SFP resp. SFP+ does not have a link speed negotiation, it's an (out of band when I have it right) control protocol between the module and the host. SFP can do Gigabit, host permitting also 100 Mb/s in an SFP slot, SFP+ can to 10G and 1G (host permitting again) in an SFP+ slot.
Before you are running crazy, be aware there are SFP+ RJ45 copper modules supporting MultiGig on the copper link - this does on the vast majority of SFP+ devices (switches) not work, as most support 10G and 1G only but _not_ MultiGig on the SFP+ slots.
At no point, the M4100-26G-PoE does support anything beyond of Gigabit. All M4100 ports, including the SFP slots, are Gigabit Ethernet only (one model verion has Fast Ethernet ports) - the SFP slots offer "100Mbps backward compatiblity on all SFP ports". -> M4100 Series Data Sheet
SFP+ modules are not workable on SFP modules.
Don't get confused about the fact that the SFP+ RJ45 modules are when powered on SFP ports auto-negotiate the link between the two modules. On the SFP/SFP+ host side, there is no such autonegotiaion, just like on fiber.
For some strange reason, I was with the impression that the SFP ports support 10gb
Thanks for the reply 🙂
Just another question, should those SFP ports not work at least at 1GB? (obviously not at 10gb since it's not supported, but should they not work at least at 1gb?)
Unfortunately no. By rule of thumb, SFP+ slots can take SFP modules (for Gb fiber links for example to connect an SFP and an d SFP+ device), but SFP slots can't take SFP+ modules.
As I said, SFP resp. SFP+ does not have a link speed negotiation, it's an (out of band when I have it right) control protocol between the module and the host. SFP can do Gigabit, host permitting also 100 Mb/s in an SFP slot, SFP+ can to 10G and 1G (host permitting again) in an SFP+ slot.
Before you are running crazy, be aware there are SFP+ RJ45 copper modules supporting MultiGig on the copper link - this does on the vast majority of SFP+ devices (switches) not work, as most support 10G and 1G only but _not_ MultiGig on the SFP+ slots.
