Hello

I recently brought MikroTik CRS305-1G-4S+IN, 2 x X520-DA1 10Gb PCI x8, 2x 10Gb SFP+ DAC cables and Rj45 SFP module . I connected cat6 cable into the sfp-sfpplus1 port with Rj45 SFP module and connected to the modem/router and finally sfp-sfpplus2 to the Proxmox server's installed x520-DA1 10Gb PCI x8 adapter.

When I go to Interfaces page in routerOS and saw no activities in sfp-sfpplus2 port but saw activities between the router and modem/router. But when I tried another method by direct connection between Proxmox and my laptop I can access the server.

I have little experience in networking and would like assistance to what steps I need to take to get the server to talk to the MikroTik router and receive internet as well?

Regards

William

Is the DAC recognized by routerOS at all? If so you can try fiddling with auto-negotiation (IE set link speed to 10gbit instead of auto). You probably have to to this on both sides.
Are you sure the x520 in Proxmox works? (Do the RJ45 SFP module work plugged in this side?).

If the DAC isn't recognized by routerOS at all its broken or not supported.

Check if the X520 is configured to allow unsupported SFP.
Inside the GRUB command line ( /etc/default/grub ) you should have:
ixgbe.allow_unsupported_sfp=1

The DAC is recongised by the RouterOS and Proxmox server can see the adapter as Intel Corporation 82599ES 10-Gigabit, but not sure what extra step I need to look into to diagnose the network excommunication?

To my observation I think Intel adapter only talk to intel branded DAC and the DAC cable I have purchased is OEM, Vender Part Number SFP-H10GB-CU2M which is compatible with CISCO products.
I purchased customized cables from fs,com so hopefully that solve the issue I am having. Will report my result next week.

I've used quite a few x520s in Hypervisors and they definitely need Intel-chipped DAC or SFPs. That's most likely your issue.