To Enable Netflow Collection on a SonicWall Firewall follow the steps defined in the following article:
https://www.sonicwall.com/support/technical-documentation/docs/sonicos8-appflow_device/Content/appflow-d-flow-reporting-user-config-netflow-v5.htm
Specify the TotalView Host as the Collector IP
The Default Listening Port as UDP 2055