So, I was under the mistaken impression that routing a /29 over my AM300-in-half-bridge would be easy... apparently not, unless It'll actually work but I'm doing something stupid on my linux firewall.
tcpdump is certainly not showing any incoming traffic on the firewall, but a traceroute on a remote host is getting to my DSL IP, just not to the host after that. Of course with half bridge my DSL IP appears twice, once on the AM300, and second on the NIC on the firewall, and it'll be hitting the first. I'm assuming that the AM300 is not very clever with anything other than the IP it gets from the connection.
I've tried various configurations - with and w/o half-bridge, with and w/o a static route on the AM300, etc etc.
Anyone got any ideas?