Thanks, when specifying a concrete MAC address using the command e.g. AT+QMAP=“mpdn_rule”,0,1,0,1,1,“AB:CD:EF:AB:CD:EF”, it is accepted and when acts as follows:
If AT+QMAP=“ippt_nat” is set to “1”, then the ISP’s IP address is forwarded to the ethernet interface, however, the DNS-server still is provided by the modem with its IP address 192.168.224.1
If AT+QMAP=“ippt_nat” is set to “0”, then not only the ISP’s IP address is forwared to the ethernet interface, but also the DNS servers.
I have to investigate this further, but at least in the AT+QMAP=“mpdn_rule”,0,1,0,1,1,“AB:CD:EF:AB:CD:EF” & AT+QMAP=“ippt_nat”,0 - scenario, I’ve already lost routing towards the WAN twice. The connection stays up, the ISP’s IP address remains assigned, but no traffic is forwarded anymore randomly until the RM551E-GL is rebooted, which obviously sucks.
@Quectel: besides this possible bug, could you please elaborate on what that “ippt_nat” - option is actually supposed to be doing? Naming-wise, it is somehow counter-intuitive that a ippt_nat (namingly “IP PassThrough”) set to zero for “disabled” actually leads to passthrough in terms of the DNS servers, while a ippt_nat option set to “1” (for ethernet) actually leads to DNS servers referring to the modem (thus not being passthrough DNS-wise).
When in doubt, I would expect it it to be the other way around.