RB751U ether1 - ether 5 all same (switch ports)

Hi,
Is it possbile to put all etherports in one swich group?
I have trouble to set ether1 as master and ehter2 till ether5 as slave.

RB751U switch-chip has 4 ethernet ports (ether2-ether5), ether1 cannot be put into a switch group because it is not the part of switch-chip.

Ok thanks,

To make a bridge and put ether1 and ether2 in it is that a good option to make all ports available as one group?

It is almost the only option to make all ports available as a one group, beside bridging them all.
Since RB751U has 100Mbit switch-chip, mainly, decision should be made depending on what RouterOS features are planned to be used: bridge firewall, STP or switch rules.