I flashed OpenWRT to a Linksys WRT54gv2 router. The setup was successful and I have been using the router as a DNS server and firewall ahead of another router acting as the gateway to a private network. It was all working fine until...
Not understanding much about routers, OpenWRT, networks, etc., I was nonetheless curious (uh oh) about the potential of using PPPoe for the connection between the two routers, with the OPenWRT/WRT54g requiring a username and password to connect, thus requiring the other router to have this information in order to establish a connection. I set up the OpenWRT LAN network to use PPPoe as a experiment. It seems to have worked far too well. I am no longer able to access the OpenWRT router by any means I'm aware of. Further, attempts to access the failsafe mode have also failed (pushing the button, or repeatedly pushing it at various times during the boot cycle has no effect whatsoever. The router no longer even appears at it's previous IP address, nor the standard 192.168.1.1, which isn't surprising as I apparently am unable to establish a PPPoE connection, which I presume it now requires.
Perhaps I'm doing something wrong with my attempt to access failsafe (unplug, set computer to static ip 192.168.1.1/255.255.255.0, connect computer to "Internet" port, plug it back in, wait until power light flashes, press reset button...). Or, perhaps PPPoe prevents failsafe from working? I'm at a loss and I'm asking for help from anyone who may be able.