I use Mikrotik 2011UiAS-2HnD for testing purposes.
Recently, I tried to connect a motherboard with a network controller X557-AT2 to the port "ETH5", but the router did not see the connected network cable. The LED indication did not light up either on the motherboard or on the router, as if there was no cable at all.
I've tried Intel X550-T2 to plug in same ETH5 port - all worked fine with 1Gbps speed.
I've tried to plug X557-AT2 motherboard to other 1Gbps switches I had (Netgear GS108 and Netgear GS105) - all was fine with 1Gbps speed.
So, I think it is incompatibility of this particular router model with this network card model.
Are there any ways to make a router with a network card?
I use RouterOS version 6.36 Bugfix, a network cable with a length of 1.5 meters of category 6.