Prevent Leakage on Fritzbox 6490

[k0ns0le 0]

Hi there, I use a Fritzbox 6490 with the current OS 6.63. My goal is to set-up the firewall of the Fritzbox in a way that only AirVPN internet traffic is allowed and everything else blocked. Can you please help and describe how to set-up the Fritzbox?

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[LZ1 662]

Hello!

 

Is this what you're looking for?

[k0ns0le 0]

Hello!

 

Is this what you're looking for?

 

​Thanks for your suggestion. But, unfortunately, no this How-To is not what I'm looking for. It's about flashing Fritzboxes with old OS's.

​I'm looking for a way to set-up the firewall of the Fritzbox running to latest official OS to only let AirVPN traffic through.

[OpenSourcerer 1359]

It's about flashing Fritzboxes with old OS's.

 

Not quite, it's about flashing postmarket firmwares. Only if you want to use iptables you need an OS version <5.0.

 

Since you use a cable modem where ~50% of an AVM reference (flagship) model's features are just not there (managed by ISP), I think it's not possible. But then again, I don't know what new features were implemented after 6.50 because this is the most recent OS version I have access to currently.

 

For me there's only the option to edit filtering lists for child safety profiles. There I can set the firewall to whitelist mode and enter all IPs I allow the devices belonging to a profile to view.

 

Freetz on the other hand would open the option to edit the AVM firewall but this is of course not an option for cable modems.

[k0ns0le 0]

Speaking of the implemented internet filters of the FritzBox: It is possible to create rules that restrict certain protocols and ports.

 

Is it reasonable to restrict all protocols and ports, except the protocols and ports the AirVPN Client for Windows "Eddie" is using?

 

In my consideration this should do the trick that the Fritzbox allows only AirVPN internet traffic and everything else blocked. Is this thought correct?

[OpenSourcerer 1359]

Is it reasonable to restrict all protocols and ports, except the protocols and ports the AirVPN Client for Windows "Eddie" is using?

 

In my consideration this should do the trick that the Fritzbox allows only AirVPN internet traffic and everything else blocked. Is this thought correct?

 

Only if you also restrict connections to AirVPN IPs. If I globally allow tcp/443, every HTTPS website can be viewed, no matter if I'm connected or not.

A workaround would be to never connect using TCP. Opening all UDP ports should do the trick. Problem: You don't take care of DNS leaks because DNS operates on udp/53 - which is a port you can connect to here.

So the best you can do is still maintaining a list of allowed IPs in an otherwise blocking filter.