I try to Forward a Port from an Anycast IP (111.111.111.111), which has multiple POP's and the Port should be then forwarded to a single Unicast IP (10.0.0.1).
All of them are reachable over a VPN, for forwarding the traffic.
There is a service listening on 10.0.0.1.
My issue is, usually you send the Traffic back to a single fixed IP, but what if the Traffic comes from 10.0.0.2 or 10.0.0.3? and not 10.0.0.4 I have configured it with. How do I configure that without multiple interfaces on 10.0.0.1.
Stuff like this:
ip rule add from <interface_IP> dev <interface> table isp2
ip route add default via <gateway_IP> dev <interface> table isp2
Is not going to work, to send the data back. Since the IP it came from could be any of them. Any idea?