Can pppoe server use whole public subnet



  • Let's say I have a static IP address from my ISP, 1.1.1.1/32 (pppoe)
    and a small subnet that they route to me, 2.2.2.0/30

    Using normal routing I would set up pfsense's LAN IP as 2.2.2.1, and my one LAN host would be 2.2.2.2. That's the end of my /30 subnet.

    Or is it? I've started playing with pfsense's pppoe server and it seems one can arbitrarily assign gateways and subnet masks to these clients and they don't even complain! Case in point, my WAN IP (pppoe) is different enough from my default gateway that it can't reasonably be on the same subnet.

    So could I assign pfsense's LAN interface an IP address of 10.10.10.1/32, run the pppoe server on that interface, and hand out all four of my /30 IP addresses to 4 different hosts? I mean, will these hosts have internet connectivity and all the perks of a publicly routable IP address?



  • I don't really understand your setup (sorry), however one thing I can say is that your ISP will not (or shouldn't) allow public IPs to be routable to you which they haven't assigned to you. That's just a simple router config on their end. If you are finding that you are able to use public IPs outside of your assigned range, then your ISP needs a good "telling off" :P

    Again, I'm sorry if I've completely misunderstood your question



  • Yeah, I meant to say that I have leased a subnet (hypothetically), so rather than route that subnet in the traditional fashion, as per my first example, what if I assigned them out as pppoe clients. Would this allow me to use all of the addresses in the subnet instead of losing the first and last, as I would in a typical routed scenario?


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