i missed your 82566mm in my previous post. ron's speculation is basically right. intel change device ids between the initial documentation and the actual product. in /sys/src/9/pc/ether82563.c makee this change and recompile a kernel:
break;
case 0x1049: /* mm */
+ case 0x1047:
case 0x104a: /* dm */
case 0x104d: /* v */
type = i82566;
break;
case 0x10a4:
case 0x105e:
i'll submit a patch.
- erik
