Configure 3G Dongle for minimal network traffic

[simonmcc]

I want to add a 3G Dongle to my project to allow remote access in a place where there is no wireless. I hope to minimise the network traffic so that only a small data allowance will be required.

I only want to let 3 network things happen:
1) OUT : dyndns update so the device can be found (or similar)
2) IN : ssh - allow ssh traffic in
3) IN : http - allow http traffic in

I also currently have my pi set up as an access point, and this is the normal way of connecting to it for maintenance etc.

Any pointers for how to configure this on the pi?

[J_Rey]

What you need is called a firewall. See the related Debian documentation. It seems you might want to consider a front-end instead of editing iptables/ip6tables yourself and there should be multiple ones available if you search in aptitude.

I'd also consider allowing firmware & system updates through unless you would manually do that with another connection periodically.