Just trying to find out if the CRS812 DDQ is backwards compatible on its qsfp56 ports with qsfp28 transceivers @ 100gbe, qsfp+ transcievers @ 40gbe, and if the qsfp56 ports are qsfp28 compatible. From what I can gather but not find out for sure - both of these are true; but it’s a little foggy and I don’t want to go into something unsupported.
Second question is, if this switch can support 100gbe qsfp28 and 40gbe qsfp+ will it do LACP over those ‘fallback speeds’ on the ports. I’ve had switches where LACP doesn’t work if you’re for example breaking out a 40gbe to 4x10gbe on a qsfp28/100gbe port; it will only work if its a 100gbe broken out to 4x25gbe.
Just in primary defense, I have searched here first it’s just that while i’ve found statements and examples touching on it, I just want to find out for sure that, for example, the CRS812 DDQ will be able to do 40gbe @ 4x10gbe as LACP to a downstream 10gbe managed switch.
If it DOES support that, well… thats pretty amazing.