Sharing public Wan IP Subnet between 2 locations (Site to Site WAN?)



  • An ISP has allocated us a /27 to use. We need to use some of the IPs within the /27 in a separate location where the ISP (transit) is a different ISP.

    Public IP Subnet (/27) <=> Pf Sense (PF A) <= Public Internet => Pf Sense (PF B) <=> Switch (servers)

    PF A has an IP of the /27 Subnet
    PF B has an IP of the other ISP.
    PF B connects to a switch where servers are connected to and make use of the /27, so the /27 subnet traffic for the servers that are making use of some of the /27 are tunnelled? through PF A.

    I'm wondering if the above is possible? Essentially taking a public subnet and sharing that in a separate location? I have been looking at Site to Site connectivity using IPSEC and have successfully setup a IPSec VPN, but this appears to be limited to WAN and LAN setups (rather than effectively WAN-2-WAN setup.

    I'm wondering if anyone could point me in the right direction to guidance, examples, how to's etc.

    We don't have to use PFSense and are flexible (it just so happens that many site-to-site examples use PFsense). Alternatively if you think there is a better or more reliable way etc, ideas are welcome.

    Network Topology is close (< 3ms latency). It is not vital that traffic is encrypted because it is public internet traffic.


  • LAYER 8 Netgate

    You could send some of that /27 across OpenVPN to the other site if the /27 is routed to you.

    If the interface is a /27 that's going to be much more difficult.