• On this example here is the case:

1. Eth1 connect to ISP (192.168.0.1/24)
2. Eth3 connect to Local Network (10.1.1.1/24)

• First, create the L2TP server:

PPP > Interface
click L2TP server
Enabled: checked
Use IPsec: checked
IPsec Secret: K@d3k&123 (example value)
Click OK

• Create the user:

PPP > Secrets
Name: vpnuser01 (example value)
Password: P@ss&123 (example value)
Service: l2tp
Profile: vpn_profile
Click OK