Hello.
I found how to do it in version 2.5:
[MikroTik] bridge> print
ip: discard
ipx: discard
appletalk: discard
ipv6: discard
arp: discard
other: discard
priority: 1
(c) http://www.mikrotik.com/documentation/manual_2.5/Basic/Bridge.html
And how to do it on version 5.14 ?
Thank you for answers.