Rut 956-can't ping/acces router via mob1sa1 int

I have an issue using RUT956 - RUT9M_R_00.07.04.3. I configured the mobile interface MOB1SA1 using a SIM card with static IP provided by ISP.
I can’t ping the public ip on MOB1SA1 interface, nor acces my RUT956 using web interface from another PC connected to internet.
I enabled all the traffic rules and firewall rules regarding acces to http/https GUI acces via WAN, also enabled PING acces on WAN zone. If i insert the same SIM card in a smartphone, i have no problem pinging the IP.
One strange thing i encounter is that anytime i’m making any change on configuration and save it, for about 20 seconds, the ping works, then the connection fails again until i make and save another change or reboot router.


Can you please let me know which traffic rules and options you have enabled? I’d like to check if everything is set up correctly.

Best regards,

Another fun fact, if i disable MOB1SA1 interface, the ping works just fine, but still no web GUI acces.

And you are sure that the correct APN is being used?
When I request a static IP on a SIM here in the Netherlands, I have to use a different APN due to firewall rules at the provider.

Can you upgrade your box to firmware version 07.07.1 without “Keep Settings” (attention: current config will be gone - but on purpose) and try again?

RUT956 Firmware Downloads - Teltonika Networks Wiki

If you can’t get to the GUI you can try the Bootloader Menu - described here:

RUT956 Device Recovery Options - Teltonika Networks Wiki

Yep, indeed, i have to configure a custom APN, but it’s configured correctly.

I will try changing the firmware and come back with an answear. Thank you!

Hi @Hakuchi321 ,

Could you tell me the firmware version you have used when experiencing this issue?

Best regards,

It says in post 1.

@TeWe , upgraded firmware to 07.07.1.
Still got the same issue. Did the proper configuration to allow ping and remote acces to WebGUI via WAN zone, but the problem persists.


You mentioned disabling the mobile interface, but pings still went through? This seems highly improbable. Maybe you are pinging the wrong address?

Best regards,

Nope. This was exactly what i thought too. But I’m 100% sure that i’m pinging the right address.


Given that you can successfully ping your device even with the mobile interface turned off, it’s very likely that you don’t have a static IP address. Please double-check if you actually have one. What address does your router get from the provider? (Please remove or obfuscate the last digits of it.)

Best regards,

I always get 172.27.X.X
I know for sure that i have static IP, because I particulary asked to my ISP for that.

You could easily test this if you setup DDNS and see which public IP is shown there.
By the way, to test your scenario using DDNS would be a good idea :wink:


The IP address you provided is not a public IP address; it belongs to a private IP range. This means you are behind your ISP’s CGNAT (Carrier-Grade NAT) and do not have a public IP address. Please contact your ISP for clarification, as they have given you incorrect information.

You can read more about public and private IP addresses here: Private and Public IP Addresses.

Kind regards,

I understand. I know about private and public ip adresses, but I didn’t think that would be a problem. Is there anything else that I can configure on my RUT in order to resolve the issue? The idea is that i have an address for an equipment, that my ISP provided, which role is to control devices that use SIM cards they gave for my network. So may i configure any static route/policy route between my routers and that equipement?

As I said, i have no problem using the SIM cards introduced in other network devices.


Your SIM card might have the necessary settings provided by default. However, you may need to configure specific APN settings given by your ISP, which is more common.

I’m not sure what you meant by this statement:

“The idea is that I have an address for equipment provided by my ISP, which controls devices using the SIM cards they provided for my network.”

In any case, you should contact your ISP for more information and to get your public IP address.

Best regards,