> If I put em0 and em1 on DHCP, and connect each to their own > gateway/router, they will get their respective configuration, but this > does not solve the problem. Consider the case where both ISPs use > 192.168.1.1/24: em0 and em1 will get two configurations for apparently > the same network, causing a conflict.
Do neither of your upstream devices support either passing through a public IP, or changing the DHCP IP range? I have two ISP connections here, and they both will hand a public IP to my router(s). Barring that, at least one of the devices allows me to change the DHCP range if I use their own firewall. Brian