Hardware Reference
In-Depth Information
Verifying port forwarding online
Port forwarding security
Many Internet service providers have started to block incoming traffic on
standard ports, normally below 1024. They usually do this for security reasons
(and not just to stop you from hosting your own servers). The vast majority of
automated attacks running rampant on the Internet only scan for listening ports
on these standard numbers.
Therefore, you can minimize the risk of having your Pi flooded with automated
break-in attempts by either creating port forwarding rules that forward traffic from
non-standard ports, or alternatively you can configure the service itself to bind to a
non-standard port.
If your router allows it, the first method is much easier. Simply add a port forward
rule like in the earlier example, but specify a different external port, for example
2222
.
To do the same thing through UPnP, you would use this command but replace
[IP
address]
with the IP address of your Pi:
pi@raspberrypi ~ $ upnpc -a [IP address] 22 2222 tcp
