PPPoE client with a public IP range

[tech-lists]

Hello list,

PPPoE (as client) seems easy enough to set up as per 
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/pppoe.html 
but what I'm trying to get my head around is how do I make use of my 
five real IPs?

So for example, on my freebsd client there's two network cards, rl0 and rl1.

rl0 plugs into the LAN port of a dsl modem/bridge that outputs PPPoE.

I want traffic from the LAN facing NIC (rl1) to be able to access the 
internet and vice-versa. Output from rl1 to the LAN goes into an 
(unmanaged) switch. A couple of machines with fixed public IPs (and 
their own firewalls) plug in there, and also a wireless router that 
serves private IPs via DHCP.

How (and where) do I configure rl1? I presume in rc.conf, maybe I need 
PF as well, but what's the syntax for an IP range?

Does rl0 need to be given an IP?

thanks,
-- 
J.