I finally managed to make it work … 🙂 So this time we are trying to establish multichannel between Debian Linux with Samba 4.9.5-Debian and Windows server 2019 (that preferres SMB 3.1.1 dialect). Each of VMs on separate Hyper-V hosts has 4 virtual network adapters connected. I entered the hostnames of VMs in hosts files both – on Windows and Linux as I am not running any DNS server in the test network.
So I added 4 entries on each machine. On Debian I have created a simple smb.conf example file to make it work:

[global]
workgroup = WORKGROUP
interfaces = eth0, eth1, eth2, eth3
bind interfaces only = Yes
vfs objects = recycle aio_pthread
aio read size = 1
aio write size = 1
strict locking = No
use sendfile = no
server multi channel support = yes
server string = samba server
security = USER
encrypt passwords = yes
smb passwd file = /etc/samba/smbpasswd
guest ok = yes

[storage]
comment = Storage
path = /var/samba
writeable = yes
public = no

As you can see in video by using Linux command in terminal: smbstatus I am getting similar information as running get-smbmultichannel Powershell cmdlet on Windows. I can clearly see how servers are connected between them by using SMB protocol.

As you can see in video Windows machine, from which I am copying data to Linux utilizes all four network adapters but we are getting only 2 gigabit throughput. On Linux side there are only two NICs utilized. I was not able to make it work by using all four adapters (like machines were utilizing in previous part in Windows VM to Windows VM scenario). Well I just wanted to demonstrate that concept works also in mixed environment with Windows and Linux.