Hello
I have a problem with using DDNS.
I’m using a SXT LTE kit router that I’ve inserted a SIM card into.
Now I’m using the basic settings (I’ve entered the card pin and have internet) but the DDNS address isn’t working for me (i think). DDNS only works on the internal network but it doesn’t respond from the outside.
I would like to do port-knocking from an external network (e.g. from a phone in another city) so that when i complete the steps (port-knocking) it will start the internet for e.g. 1h. in my home
I’ve managed to do it before from an internal network, but no packets are coming from the outside to the specified (open) ports.
Of course DDNS is enabled
I use a SIM card which has a dynamic ip address.
thank you
Is your carrier using CG-NAT and is your router getting a true routable public IP address?
i’m using a regular operator’s plan, but I don’t think it has this
“is your router getting a true routable public IP address?” can i check it in the router?
If it’s a regular operator’s plan, it depends where in the world you are, but it’s quite likely to be CG-NAT, where you get a private IP address from the carrier.
You can check by running
/ip address print
and seeing what the IP is for your WAN interface.
okay i did it
files in attachments
conf.rsc (2.84 KB)
Ok, that is a Class A private address, so your operator is using CG-NAT.
Unfortunately, that means you will not be able to host any services or do any port knocking unless you use some intermediate VPN or something.
Basically CG-NAT means that there is no public address that is only for you, so there is no way for you to accept incoming connections on this router, unless you accept incoming connections on a VPN interface where you first make an outbound connection to a VPN server that does have a public IP address.
My operator offers a service that has a description: “Orange VPN static provides access to the Internet with a public IP. Thanks to the service, a customer using mobile internet as home internet can use multimedia features such as smart home, connection to webcams, online game servers, etc.”…“Orange VPN is a service that allows you to access the Internet with a public IP address (dynamic or static) from a device equipped with a SIM card This allows you to gain remote access to that device.” (I translated this) can it help?
It might, it depends on what they are using for their “VPN” offering. Without more information it is not possible to be more precise.
so what do i need to know to use port-knocking. i am going to contact the operator and what do I need to know?
You need to know if all ports for a given Public IP address can be forwarded to your private IP address.