CCR2004-1G-12S+2XS and CRS354-48G-4S+2Q+RM QSFP to SFP28 possible ?

Hardware MikroTik hardware general
1

I am thinking to grab a CCR2004-1G-12S+2XS and a CRS354-48G-4S+2Q+RM switch.

The Router doesn’t have a QSFP+ like the switch.

Getting this converter:
https://mikrotik.com/product/xq_cm0000_xs_#fndtn-specifications
XQ+CM0000-XS+

And a DAC like this:
https://mikrotik.com/product/xs_da0003#fndtn-specifications
XS+DA0003

Can I connect the Router’s SFP28 port to a QSFP of the switch and achieve 25G ?

2

You cannot achieve 25G, because QSFP+ cannot “divide” lanes in that fashion (it consist of 4x10Gb lanes, SFP28 is 1x25Gb).
IF it even worked with mentioned adapter and DAC, you would get 10Gb max.
On the other hand, connecting QSFP28 (100Gb) and QSFP+ (40Gb) is possible.