Thankyou all for your comments. You've certainly given me some things to look into. FWIW, I've conducted my own tests and seen generally sub-ms accuracy, with occasional spikes. Manually loading the system as it would be in production has negligible affect on the accuracy of the timing. Unfortunatel...

Firstly, I apologise if this has already been answered elsewhere. It is not my intention to duplicate existing questions. I simply can't find a direct answer to my questions. Given that the RPi runs a Linux system and that I'll be programming in Python, both of which introduce potential delays to ti...

Are you using bridging or routing ? if you're bridging, iptables *shouldnt* come into it. If you're routing, then it's not really bridging, and you just setup iptables like a router. I'm not bridging the connections; I'm routing using iptables. I still have to figure out why iptables isn't routing ...

I've actually almost completely managed to do this. The only problem I'm having is routing DHCP and DNS requests to the router using iptables. Maybe there's something I'm missing, but if someone know things about iptables (I'm hardly a linux noob, but iptables confuses the hell out of me) I'd apprec...