ZTE MF823 4G - change IP of Modem and get Public IP forwarded to the Router...

The ZTE MF823 4G Modem is a kind of Modem which you Plug in to the Router or Computer and it should just work. Yes it does.... You Plug it in and the connection is already established.

This makes since a bit more difficulty as the Modem has its own DHCP and IP Range which it uses. The Modem has also its own Firewall which blocks all incoming traffic. As I have a public IP and use the Modem with my Router, I would like to get the WAN traffic forwarded to my Router.

I couldn't manage (yet) to get the real "Port Forwarding" working, but as after the modification I could use the DMZ where I entered the IP of my Router. So this means that all the traffic coming to the public IP will be forwarded to the Router where the Router Firewall will block stuff if needed.

For the connection to the Modem we just need to do a telnet which can be done from Windows or Putty which I prefer. The IP for the ZTE MF823 4G is standard 192.168.0.1 what I didn't change yet.

The Login and Password are the below:

Username: root

Password: zte9x15

After successfully login to the modem it should look like this:

 OpenEmbedded Linux 9615-cdp  
 msm 20130829 9615-cdp  
 9615-cdp login: root  
 Password:  
 root@9615-cdp:~#  

There is the ZTE Web application which is located in the following folder in the modem: /usr/zte_web/web and the categories are located in the folder: /usr/zte_web/web/js/ which looks like this:

There we can see that there are all kind of different categories which could be added to the Web Interface menu. Well you probably know but the Web Interface you just open in the web browser with the IP of the Modem (default 192.168.0.1). As I want to have the WAN traffic forwarded to my Router, I mostly interested in the stuff under firewall where we get the following:

Now the best part is making all this stuff visibility in the web interface so we can finally change those settings. All this what should be displayed in the web interface is locate in 1 file: /usr/zte_web/web/js/config/datacard/mf823/menu.js . This file we need to modify with the editor which we got on the modem "vi" But wait.... always better to have a Backup so if some goes wrong we can recover the the file. 

 cd /usr/zte_web/web/js/config/datacard/mf823/  
 cp menu.js menu.js_org  

This command will go to the folder and copy the original file to menu.js_org so we still got a Backup for recovering purpose. So now we can open the file with the command:

 vi menu.js

I will not go to explain on how to use vi because I believe Google knows how to use it....
Almost at the end of the file you will find something like this:

  {^M  
       hash:'#pin_management',^M  
       path:'adm/pin',^M  
       level:'3',^M  
       parent:'#device_setting',^M  
       requireLogin:needLogin,^M  
             checkSIMStatus:true^M  
     },^M  

Not sure why it shows up by me like this: "},^M" .... but it should be for the stuff we paste just like this "},"
That is probably because of the coding I use in Putty or whatever other reason. So after this we can just paste the following text to enable all this Feature on the ZTE MF823 Modem:

 {  
     hash:'#port_forward',  
     path:'firewall/port_forward',  
     level:'3',  
     parent:'#device_setting',  
     requireLogin:false,  
     checkSIMStatus:false  
     },  
     {  
      hash:'#router_setting',  
      path:'adm/lan',  
      level:'3',  
      parent:'#device_setting',  
      requireLogin:false,  
      checkSIMStatus:false  
      },  
     {  
     hash:'#dmz_setting',  
     path:'firewall/dmz_setting',  
     level:'3',  
     parent:'#device_setting',  
     requireLogin:false,  
     checkSIMStatus:false  
     },  
     {  
     hash:'#upnp_setting',  
     path:'firewall/upnp_setting',  
     level:'3',  
     parent:'#device_setting',  
     requireLogin:false,  
     checkSIMStatus:false  
                             },  
     {  
     hash:'#port_filter',  
     path:'firewall/port_filter',  
     level:'3',  
     parent:'#device_setting',  
     requireLogin:false,  
     checkSIMStatus:false  
     },  

As I mentioned above, it is without the ^M  And the end of the file there will be still the menu for the update and this should stay there. Not even sure if this works, as I never received any Updates :-) After this changes are made you can save the file and refresh you web interface and you will get new cool stuff in there which is for sure helpful:

All the new Entries you can find under Device settings as you can see on the above screenshot. As I mentioned on my device I get an FAILED when I try to enable the Port Forwarding, but all the other stuff works fine for me and I can access now my router from the public IP. Be careful with changing the IP Address of the modem, as it could fail to boot when you enter some wrong settings there.

So use it on your own Risk. My first Modem ZTE needed to exchange as it didn't work anymore after trying to make this Modem to a dial up modem :-) But ZTE just exchange the modem.... Thanks!

Also thanks to http://www.elevendroids.com/ and https://wiki.archlinux.org for the information usernames and password.