The same you wrote in manual ... why doesn't Teltonika share even one example singed by company as working example?
For example when I add rule to custom rule via WebUI nad 'save'.
iptables --append INPUT --protocol tcp --src <specific_ip> --dport 80 --jump ACCEPT
iptables --append INPUT --protocol udp --src <specific_ip> --dport 80 --jump ACCEPT
I should be able to connect to device via port 80 only from <specific_ip>?
But still I can connect to router via port 80 from any other IP.
I used shorted version of parameters and reboot device but still custom rules with restriction to the device does not work for me
(device: RUT9XX_R_00.06.05.3 )