The Mikrotik CRS305 and S+RJ10 SFP+ module arrived and have been implemented. The S+RJ10 module and my existing Wiitek modules all seem to report the correct speeds but I'm going to use the S+RJ10 on my Aquantia 5Gbps NIC as it's the one causing me the most trouble. Still waiting for Asus to supply a working firmware update tool for the onboard NIC.Thanks! I've ordered a CRS305 and one of the Mikrotik S+RJ10 SFP+ modules just in case my Wiitek doesn't work. I'll hopefully have success later this week when they arrive.
There's a firmware download from station-drivers.com that supposedly has a modified xml file. That file holds the system IDs that are valid for the updater tool to work. The modded file was supposed to work for onboard NICs on Asus motherboards, but apparently not for all Asus boards. Mine's a Prime x299 Deluxe II and it won't upgrade the NIC firmware even though it detects it and sees that the firmware is out of date.
But even as it stands, the Mikrotik is allowing me to get up to 3.5Gbps speeds in both directions vs the sub-1Gbps speeds in one direction when both systems were connected directly to the ICX6610 SFP+ ports. The speed will hopefully improve further once the NIC firmware is updated. I have my unRAID servers both connected to the Mikrotik and then a DAC cable to the ICX6610.
I'm still learning about all the features of the CRS305 - I'm running it with the SwitchOS firmware instead of RouterOS as my pfSense system handles my routing requirements. I'm trying to figure out if I should use port isolation or VLANs to segregate the 1Gbps management port from the 4 x SFP+ ports. Any suggestions?
Thanks again for the assistance provided so far!