Crash if ipv6 DNS server configured in system

[zhovner]

Traceback (most recent call last): File "Responder.py", line 257, in <module> main() File "Responder.py", line 180, in main from poisoners.LLMNR import LLMNR File "/usr/share/responder/poisoners/LLMNR.py", line 57, in <module> IsICMPRedirectPlausible(settings.Config.Bind_To) File "/usr/share/responder/poisoners/LLMNR.py", line 49, in IsICMPRedirectPlausible if x !="127.0.0.1" and IsOnTheSameSubnet(x,IP) == False: File "/usr/share/responder/poisoners/LLMNR.py", line 34, in IsOnTheSameSubnet ipaddr = int(''.join([ '%02x' % int(x) for x in ip.split('.') ]), 16) ValueError: invalid literal for int() with base 10: 'fdd1:232b:380c::1'

[lgandx]

Thanks for your report. Unfortunately Responder has no support for IPv6.

[Jake3231]

@zhovner are you using macOS? If so, I found a way to get around this issue.

[zhovner]

@Jake3231 yes, i'm using macOS 10.13.3. What the solution?

[Jake3231]

It turns out that in the network preferences in System Preferences, you can sort of disable IPv6.

1. Open System Preferences and select the interface you are using in the left sidebar. From there, you may need to unlock the preference pane by clicking the padlock in the bottom left corner of the window.
2. Select Advanced and navigate to the TCP/IP tab in the sheet that drops down.
3. Next to Configure IPv6: there will be a drop down in which Automatically will be selected by default. Change that to Link-local only. Now the error should not occur.

[zhovner]

Thank you, but this is not a solution for me. I can remove ipv6 from the system but I really need it and use it.

[Jake3231]

Okay. I'm now aware of any other solution, unfortunately. If you are able to work without IPv6, this will at least allow Responder to work. If I find a way to make this work without disabling IPv6, I will let you know.

[videoman]

You could also try using the current version of responder here: https://github.com/lgandx/Responder no updates to this project have been made in a long time.