connecting 2 FS728TP via sfp port

Hi JohnRo,

Thanks for getting back to me. Heres what I'm trying to do. My firm is expanding its office and taken on some new vacant floor space on the other side of the building. So I need to connect this office (call it Office-A) to the new office (call it Office-B). The connection will have to carry voip, data and internet traffic on two seperate networks, linked together with OM4 Multimode, 8 core, fiber cable, terminated in each offices server room at a patch panel. This then has four connectors which will go to a variety of switches via sfp modules.

For the moment Im focussing on the voip network which in Office-A is made up of 3 Netgear FS728TP switches stacked together via ethernet cable to Office-B which will have one brand new FS728TP. The SFP modules in the Netgears are all AGM731F sx\lc connectors with 2m OM4 MM sc\lc fiber cables running to the patch panels. The problem is I cant get one side to see the other and from my understanding you shouldnt have to configure anything on the Netgears apart from an ip address (all in the same 192.168.83.0 subnet) for it to work. After a lot of fault finding I pulle done of the switches from Office-A and installed it into Office-B, linked it to the new switch via ethernet and checked they coudl see each other, (which they could). Then connected the fiber cable, ran the management app and was still unable to detect the other side. I also connected one of teh voip phones (known to work) to the new switch and still no joy.

Checks carried out include:

Making sure the fiber port at either end wasnt sharing the ethernet port for the existing stack

Swapped sfp modules around (dont have any spares and tried some from Cisco anyway)

Tried different 2m fiber cables

Tried the sfp ports on 2 cisco 10 port switches

Rebooted everything

Tried different patch points

All without success. The only difference I can see is that the firmware version are different (Office-A switches have been in there for at least 3 years) but I dont think that would make any difference. Running a cable check from the Switches Web gui reveals port g25 (which has the fiber cable attached) is down but there is an unknown cable type installed. So unless I'm missing something in the config (and I've looked extensively) my best guess is that theres something wrong with the fiber cable in the ceiling or the patch panels. I do have the engineer coming back in today to check it but is there some obscure setting I am missing?

many thanks