Verify the network paths actually selected by SMB Multichannel

Source facts

SMB Multichannel can use several network connections at once between an SMB 3.0 client and server, enabling bandwidth aggregation and network-path resilience where multiple paths exist. Microsoft states that it is enabled by default and does not require installing another role or feature. The client discovers and uses multiple connections when it identifies a qualifying configuration. Microsoft documentation.

Applicability

Inventory the client and server versions, network adapters, capabilities, paths, and source prerequisites. Review the actual configuration before assuming that multiple physical ports or a team necessarily proves multichannel use.

DSE recommendation

Record the intended paths and the workload whose traffic should use them. Have the file-service and network owners agree on an acceptance test for both throughput and a permitted path interruption. Keep the original adapter and SMB settings available for comparison.

Verification

During a controlled file operation, inspect the established SMB connections and compare them with the approved path inventory. Measure the workload and test a planned path interruption where authorized. Preserve the selected connections and application result together, and investigate an unused expected path before declaring the design validated.

Official references

Microsoft Learn: Manage SMB Multichannel. Source reviewed September 8, 2026.