Connect M5300 & S3300 via SPF

Hi autoitaus

I am sorry about your issue. I am also sorry you didn't make it easy for anyone to understand your issue, it took too much guess to read your posts.

The M5300-52G switch (GSM7252S) has its last 4 copper 1000BASE-T RJ45 ports (45-48) combo ports, they are shared with the last 4 1000BASE-X SFP fiber ports. The port 46 you are mentioning must be the SFP shared 1G port. You are trying to use a 10G SFP+ Direct Attach Cable (AXC761) with this 1G SFP port. This can't work, the DAC cable is 10G SFP+. There can't be any link with any SFP+ fiber DAC or transceiver when connected to a 1000BASE-X SFP garage port. This, for any brand and any type of switch. There is no upward capability with fiber in general, only backward capability if any. The 1000BASE-X SFP fiber ports can only connect 1G SFP transceivers or DAC, or 100FX if supported - but never ever 10G SFP+ modules.

Your S3300 switch on the other side has 10GBASE-X SFP+ ports. This port can be ok with either 10G SFP+ transceivers/DAC or 1G SFP transceivers (backward compatibility is supported on these models).

For your uplink between these two switches, if you want to continue with the AXC761 10G SFP+ SFP+ DAC cable, you should use a 10GBASE-X SFP+ fiber port on your M5300-52G switch, maybe the shared ports 49-50 on the front. If you really want to use a 1G port on this switch, you should revert to 1G fiber transceivers on both ends (like AGM731F and MMF patch cord). Or a 1G grade DAC cable made of SFP connectors for 1G connections (that will have to be third-party, as NETGEAR doesn't carry such DAC cable in its portfolio).

I hope this helps,

Regards