We have a situation that I'm not sure how to proceed correctly.
This location is currently utilizing two different firewalls - a Sophos XG 310 and a Sonicwall NSA 3500. The way this was originally configured, a small switch was put in place before the firewalls, with one ISP connection coming into the switch, then one connection from the switch going to each firewall. They have one public IP from their ISP going to the Sonicwall, and one public IP (for the same ISP connection) going to the Sophos.
I am wanting to move the public IP that is currently on the Sonicwall to the Sophos without disrupting the flow of traffic to the ISP. They have several services that use the public IP that is currently on the Sonicwall.
How can I move the connection from the Sonicwall to the Sophos as a second interface for the same ISP and allow communcation for the services to work properly?
Best description I can come up with is that ...120 has a NAT for connecting to Remote Desktop Gateway with ...120:45678. I want to move the ...120 interface from the Sonicwall on the left to the ...121 Sophos on the right. Do I create a second interface on the Sophos, then create the NAT and firewall rules? Seems off to me to have two different public IP's on two different interfaces from the same ISP pool. There are even more services on the old Sonicwall in addition to the one I described, but trying to keep this as simple as possible.