If you are unable to provision the ADSL modem, you must make the OpenBSD router into a NAT router. In this way, OpenBSD will translate the addresses for all traffic routed to and from the second network. This is done with the
nat-to directive in PF, as described in the
Network Address Translation chapter of the
PF Users' Guide.
When you have NAT routers linked together -- "double NAT" -- this can cause problems for some protocols.
Something like this might work:
Code:
pass out on em0 inet from em1:network to any nat-to (em0)