Does a UPnP portmapping update automatically when the local computers IP updates dynamically? If not then how will you remove the old port mapping if you now have a new IP and will not be "authorised" to do so.
Suppose I could forward right before and remove right after I need the connection to be made. My issue is; what if the computer shuts down mid connection and turns back on with a different IP? Surely something must've been made in order to circumvent this.
Found an answer
UPnP is soft-state.
In [1], section 4.1, PortMappingLeaseDuration is described as a state variable that describes that a mapping is only leased for a certain duration. (indeed soft state) also [1], section 5.10, describes that if your router is set up as DHCP it must delete any IGD state for that IP if it changes