It appears m0n0wall will let you forward packets back and forth using proxyarp and some NAT tricks. I am wondering if the latency of doing things like this is an issue or not. That is if I decide to keep my ISPCONFIG box on a non-broadcast IP with a firewall (like m0n0wall) on the WAN to do a proxyarp and NAT translations inbound/outbound for the 5 IP's I have access to. Is the latency of the third party firewall significant or nominal? Or am I better off just running the ISPCONFIG box right on the pipe with only the internal firewall? Certainly easier to configure!
Again, any opinions on this or mirroring as described in the original post welcome.