UPnP is not working behind NAT

[scegg]

Hi there.
My router is AX1800, using official firmware.
It seems that UPnP support is removed and the latest miniupnp is not working behind NAT. Sadly my ISP provides only 100.64 IP instead of public accessible one.
Any idea to get the old version of miniupnp? Or other solution?

Thanks.

[luochongjun]

Maybe you can try fullcone function.

GL-MT3000 NAT type B to NAT type A?

Please try to install attached ipk. fullcone.ipk.zip (12.4 KB) upload uncompressed ipk to MT3000 /tmp/ directory. ipk source is from here. Then install and enable fullcone NAT opkg install /tmp/kmod-ipt-fullconenat_5.4.211+2022-02-13-108a36cb-10_aarch64_cortex-a53.ipk opkg install /tmp/iptables-mod-fullconenat_2022-02-13-108a36cb-10_aarch64_cortex-a53.ipk modprobe xt_FULLCONENAT iptables -t nat -A zone_wan_prerouting -j FULLCONENAT iptables -t nat -A zone_wan_postrouting -j FULLCONENAT I f…

[groentjuh]

@luochongjun, I do not believe fullcone-nat works behind carrier-grade NAT (CGN).

Scegg, what are you trying to do?

Port forwarding cannot be done behind CGN, because the CGN already stops incoming packets. So even with port forwarding setup properly, no incoming packets will reach the AX1800, because CGN stops them before they reach the AX1800.
UPnP is simply a service allowing devices on the network to make/setup a port forward to them, so that will not work either! It might setup the port forward correctly, but like a already said: all packets will not get passed CGN.

[scegg]

@groentjuh, I think you are right.

First, I just want the warning messages from miniupnp disappeared. But after digging, I guess that the upnp is totally useless under CGN. So the right thing to do, is simply remove the upnp component.