【NGAF】Unable save VPN Basic Settings prompts subinterface conflict occurred.

Issue Description

When try to make changes on the VPN Basic Settings module it was unable to save the settings. The Error message: "link interface (eth2) or its subinterface conflict occurred"

Error/Warning Logs

Handling Process

1. If the VPN path is unable delete may disconnect NGAF with Central Manager (BBC).
2. Delete one of the subinterface VPN path.
3. Save the settings.

Root Cause

The NGAF restrict to use 2 subinterface form from a same physical interface.

Solution

1. Delete one of the subinterface from the VPN path.
2. Implement the second WAN as another subinterface (differnt physical interface).