Best strategy to Speed up backup transfer rate between Datto device and Hyper V - Host

I have a Hyper) V host with 2 intel Gigabit 2 P  network cards running 3 guest Servers . I need to back them up to a Datto ZFS device on my network.
The problem is that these are both connected to 10/100 switches .
As a result i am only achieving 7.5 mb/s transfer speeds . I have 2 terabytes of data to backup with incremental . As you can imagine these backups take DAYs to complete !!  I know I need to upgrade the channel between these two machines ( Indeed the entire Lan )
What I need to know short term is how  to provide a way that the Datto device can reach the maximum transfer speed the server can produce .
My plan is to attach one of the cards to a very fast switch or even directly to Datto . I am even open to installing an even faster method .
My question is what strategy you are using or would recommend for your own connectivity . ?
I have attached the device manager page from the host so you can see what I have to work with .
Thanks
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