Ubuntu – What are the possible threats if internal IP address is publicly revealed


In many cases, people do not take enough care to remove their IP addresses from some output before posting it to help forums and Q&A sites like askubuntu.

Considering one's IP address is revealed publicly, what are the possible threats he/she/bot may face and what can one do to avoid them?

Also, is there any threat in revealing other data like Broadcast address, Subnet mask, Default route, Primary DNS and Secondary DNS ?

Of course we will consider that the person/bot is using a supported version of Ubuntu or it's official derivatives.

Best Answer

Giving out your public IP address simply makes you a target. It is like posting your email address. Malicious people will then be able to use your IP and target your computer. Whether they will be successful or not depends on the way you've set up your machine but in any case, the first step will be getting your public IP.

Now, posting your internal IP, is not dangerous at all. For example, my current internal IP is There are certainly thousands of computers all over the world that are connected to their local LAN using the exact same IP. Internal IPs are just that, internal, they have absolutely no meaning outside your own network and sharing them is not dangerous.

The same goes for the rest. All of the information you mention is specific to your local network (assuming you mean the broadcast address of your internal IP, not the public one) and there is no danger in sharing them whatsoever. In fact, please make sure to use real addresses when you ask questions since they can help us understand where the error lies.

In summary, you don't really want to share your public IP or the MAC address of your network card but internal IPs, broadcast address, subnet mask, default route (that's just the internal IP of your router) and DNS servers can be shared with no risk. DNS servers are public anyway and all the rest are internal to your local network and have no meaning outside it.

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