Scapy Python 3 Error: WARNING No route found (no default route?)

Question

I started to study Scapy today and I am getting a message: " WARNING No route found (no default route?) ." I am also a new Ubuntu user.

The name of my question sounds like a duplicate of the question Hide Scapy Warning Message IPv6. Hide Scapy Warning Message IPv6

However, when I used that solution, I do not get the warning but the problem continues.

Moreover, when I continue with other commands the problem persists.

I am using the " official " Scapy tutorial that is in this link: https://scapy.readthedocs.io/en/latest/usage.html

I am running Scapy on Python 3 over the Ubuntu 20.04 terminal. I installed Ubuntu using the Microsoft store (I am NOT using Oracle Virtual Box or something similar).

These are the commands:

a=Ether()/IP(dst="www.slashdot.org")/TCP()/"GET /index.html HTTP/1.0 \n\n"

hexdump(a)

This is the result that I am getting:

This is the result that I am supposed to get:

I am using a laptop and a wifi connection. I am running this code at home.

Thank you for your help!

PS In Ubuntu, when I use ifconfig I get the following:

PS #2 I uninstalled Ubuntu 20.04 and installed Ubuntu 18.04 and I still get the same problem.

PS #3 I installed Ubuntu 20.04 in an Oracle Virtual Box Machine, and I got a different message that got me some ideas about the possible causes of the problem. I posted a solution. Please read it, and let me know what you think.

Answer 1

It seems that the cause of the error is that as I am not using a wired connection, I am not using the network card. For that reason, the Ether() function cannot be used. As every network card has a unique Mac address, the Mac address cannot be used. That, in my opinion, is the cause of the error. Of course, I would love to have an opinion of somebody who knows more about the subject. My college degree is in mathematics. In my last attempt, I installed Scapy on an Oracle Virtual Box Machine, and I am getting the following message:

WARNING: getmacbyip failed on [Errno 1] Operation not permitted WARNING: Mac address to reach destination not found. Using broadcast.

What do you think?

@Carcigenicate advised me to use the route command in Linux.

Here is the info that I get when I use the command route in the Ubuntu terminal that is in my Oracle virtual box machine.

When I use the command route in the Ubuntu terminal that is in my Windows 10 Pro Laptop, I get the following:

At this time, following the tip of @Carcigenicate, we find that the Gateway is 0.0.0.0

What that exactly means? Not sure. Check this link: https://en.wikipedia.org/wiki/0.0.0.0

I forgot to mention that my machine is a corporate machine. So, most likely my machine has some IT security software that causes that behavior.

Answer 2

I too faced the same problem:

WARNING No route found (no default route?)

I am using kali Linux, and this is how I solved that problem. I installed the PyX package for my OS and it worked out. I can't say definitely that this is the answer to your problem, but you could try it.

pip install PyX