I just got a VPS with an IPv4 address as well as a bunch of IPv6 addresses configured and I'm new to routing in Ubuntu/Linux. I would like to route requests with a specific IPv6 and port (i.e. port 80) as destination to a specific port on that address (i.e: port 8000).
In pseudo-code, what I want is the following:
if($DESTINATION_IP == [specific IPv6-address]:80) route to port: 8000
When an application is listening on [specific IPv6-address]:8000, it will receive the requests sent to [specific IP-address]:80. But when I use [another IPv6-address]:80, it will not route to that port.
It seems pretty simple and I think I would have to use ip6tables for the job, but I don't know how to achieve this.