“Modem” (= bridge) mode on Netgear DG632

Recently I configured a Netgear DG632 in a bridge mode. Initially I was expecting the modem to translate from PPPoE on the LAN port to PPPoA on the WAN port. Wrong :)

In short, the configuration :

                                             ---- Machine 1
((Internet))----[ DG632 ]----[ Gateway ]----|---- Machine 2
                                             ---- Machine N

Actually, it dials the ISP and identifies itself just as in the router mode, but the difference is that it expects to find a computer with the public IP on the LAN port. However the router that you gateway must use is not the one given by IPCP, and rather the management IP of the modem. Here’s the relevant part of my FreeBSD’s rc.conf:

ifconfig_re1="inet 193.251.78.150 netmask 255.255.255.0"
static_routes="adsl"
route_adsl="-host 192.168.1.1 -iface re1"