--- sys/dev/ixgbe/if_ix.c.orig	2016-09-23 19:35:00.375226000 +0700
+++ sys/dev/ixgbe/if_ix.c	2016-09-23 19:38:32.539779000 +0700
@@ -577,6 +577,10 @@ ixgbe_attach(device_t dev)
 		    "who provided you with this hardware.\n");
 		break;
 	case IXGBE_ERR_SFP_NOT_SUPPORTED:
+		if (allow_unsupported_sfp) {
+			device_printf(dev, "Unsupported SFP+ Module (ignored)\n");
+			break;
+		}
 		device_printf(dev, "Unsupported SFP+ Module\n");
 		error = EIO;
 		goto err_late;