here is my setup:
laptop <-USBThetering-> mobile phone <-4g internet-> ... homeADSLrouter <-LAN-> server
- Laptop's IP is 192.168.x.x
- mobilephone internal IP is 192.168.x.y
- mobilephone external IP is .... changes every time
- homeADSLrouter external IP is variable also (though dyndns is used to update a specific host to point to that IP)
- homeADSLrouter has ability to let though ssh traffic and redirect it to server
- server has sshd server running listening on normal port
As the mobile phone's external IP changes every time, is there some mechanism still to restrict access to ssh port on the homeADSLrouter perhaps that is not based on IP but some other mechanism on top, rather than allowing all the world to be able to connect to ssh server (of course user/passwd is still a restriction but I'd prefer a little more)