6.23.1 version has x86 driver firmware fixes (few old Network Interface Cards might not work properly).
Update is not needed for RouterBOARD users.
x86 all-in-one package,
http://www.mikrotik.com/download/share/ ... 6.23.1.npk
x86 all packages,
http://www.mikrotik.com/download/share/ ... es_x86.zip