GlobalProtect Split Tunnel is not working correctly for SMB file transfer

• GlobalProtect Split Tunnel has been configured for specific destination IP address (Access Route - Exclude).
• "route print" shows the route to the specified destination is towards the physical adapter. 
• All traffic except SMB traffic is correctly going through the physical adapter such as ICMP. 
• However SMB traffic (file transfer) seems to be going into the GlobalProtect VPN tunnel to the same destination. This can be seen via Wireshark.
• The SMB traffic is seen on both the physical adapter and also the GlobalProtect VPN tunnel.
• What is expected is to see all the traffic to the destination going through the physical adapter only.

• GlobalProtect
• Split tunnel enabled
• SMB file transfer
• SMB Multichannel enabled on client

• SMB traffic is not adhering to the route is due to SMB Multichannel.
• SMB multichannel will forcefully bind connections to any interface with a route, regardless of preferred routing from the route table.
• Once the TCP session is established, SMB then transmits at the lowest available bandwidth setting between all connections - because the VPN tunnel is the slower connection, this can cause degraded transfer rates.

Note:

• SMB Multichannel is enabled by default on Windows machines. It can be verified using the following PowerShell command and output:

Disabling SMB Multichannel would allow SMB traffic to be split tunneled.

1. Enter into Windows PowerShell.
2. Type command: Set-SmbClientConfiguration -EnableMultiChannel $false