RT-AC86U: "PCP MAP: failed to add mapping TCP" error every 15 minutes

[vaboro]

Uh, why?

Just to get gid of «PCP MAP: failed to add mapping TCP 9» message.
Thank you for your prompt reply.

 

[RMerlin]

Just to get gid of «PCP MAP: failed to add mapping TCP 9» message.
Thank you for your prompt reply.

No, I meant why would you want to allow one port below 1024 but explicitely reject any other? You are already allowing a privileged port, so might as well allow them all, and just use 1-65535.

 

[vaboro]

No, I meant why would you want to allow one port below 1024 but explicitely reject any other? You are already allowing a privileged port, so might as well allow them all, and just use 1-65535.

I would want to keep the default settings of miniupnpd not allowing mapping of privileged ports in general, but to map just one privileged port to get rid of «PCP MAP: failed to add mapping TCP 9» message. I just don't know how this task might be possible to accomplish with web UI alone without resorting to the help of custom scripts.

 

[ColinTaylor]

I would want to keep the default settings of miniupnpd not allowing mapping of privileged ports in general, but to map just one privileged port to get rid of «PCP MAP: failed to add mapping TCP 9» message. I just don't know how this task might be possible to accomplish with web UI alone without resorting to the help of custom scripts.

You can't do it in the GUI you have to use the custom script. Or better still fix the problem on the source PC.

 

[vaboro]

You can't do it in the GUI you have to use the custom script. Or better still fix the problem on the source PC.

I don't think it's a problem. Discard protocol uses port 9.

 

[ColinTaylor]

Discard protocol uses port 9.

True. But it makes little sense that something would actually want to forward that port from the internet to a device on your LAN. I think it's more likely to be for the reason I mentioned in post #7.

 

[vaboro]

True. But it makes little sense that something would actually want to forward that port from the internet to a device on your LAN. I think it's more likely to be for the reason I mentioned in post #7.

The references provided in your post #7 make perfect sense to me now: «Client software that just wishes to display the user's external IP address for cosmetic purposes can achieve that by requesting a short-lived mapping (e.g., to the Discard service (TCP/9 or UDP/9) or some other port) and then displaying the resulting external IP address.»