Hello, I have a Vigor 2910VG

I want all traffic on port X to be forwarded to computer at ip address Y, port Z.

This is fine, I use NAT, Port Redirection.

I want to restrict this even further and say that as above "I want all traffic on port X to be forwarded to computer at ip address Y, port Z." BUT ONLY if it has come from a particular external ip address (which I know)

Any ideas on the best way forward?
Thanks.

You can restrict traffic as much as you like by using Firewall/Filter-setup.
You shoule be able to get what you like with multiple rules, but make sure you get them the right way round.

i.e. use the 'pass immediately' rules BEFORE the 'block immediately'.

I hope this helps...