That is exactly what i have done. The only problem is that the "dotted line" is the 2nd IP from the ISP and because of that they don't share the same Public IP (it will be XXX.XXX.XXX.250 for Primary and XXX.XXX.XXX.251 for the Secondary).
Hello @shiprasahu93 Thank you for the fast response. Thank you for the documentation, everything is configured as in there. My follow up question is: Do i need a second line with the same IP on the ISP router, for backup Firewall and one for the LAN? Thanks