Just to informa and create a topic about it. Tested Full cone NAT with GL-MT6000 and GL-MT3000. Both works fine on DHCP but don’t on PPPoE. Tested with Nintendo Switch with gives a NAT type “A” when full cone NAT is working.
I even connected MT6000 as PPPoE and MT3000 WAN to MT6000 LAN (DHCP) and full cone nat on MT3000 works (and of course, in MT6000 don’t works).
just trying to figure out how to activate fullconenat on PPPoE but no success so far. I’m thinking to try with valina openwrt (or x-wrt, immortal) to see if works
When using pppoe, does the ISP network has firewall?
I can confirm that Full NAT does not work while using PPPoE. Same issue here on my Flint2 with a Telekom VDSL connection (so no CG NAT)
I just checked and in bridge mode, my ISP modem has the firewall disabled. DHPC mode works fine (put the router in DMZ).
Also as I said in the 1st post, I also connected MT6000 as PPPoE and MT3000 WAN to MT6000 LAN (DHCP - DMZ) and full cone nat on MT3000 works (and of course, in MT6000 don’t works). So no ISP problem.
as a suggestion, the version of immortalwrt and x-wrt works correctly, but both do not use iptables but nftables, this could be the cause of the problem…