NMAP: All ports open?

I had this problem with PPtP VPN setup - the tutorial said to add a firewall rule to accept all traffic from ppp* interfaces (because the VPN driver creates interfaces ppp0, ppp1 etc.), so I configured it like that, but the tutorial author did not imagine someone could connect to WAN via PPPoE, which creates interface pppoe-wan. So I really had all ports open to the internet because of this tutorial. So the risk that @Tomov did some similar configuration mishap and really has all ports open is real.

Is it worse than trying some nmap web tools on the internet?

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Giving it out on a forum full of tech-savvy people? I would say yes :smiley: (but I also have high belief in the ethical orientation of most users of this forum :wink: )

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Sorry, I donā€™t get it. There is no open port without a service. Ports arenā€™t just open, but you need a process that binds it. The OP explicitly asked about why nmap shows almost all ports as open. It still looks like a false positive and looking at the running services, one should immediately see the ports that are really open.

The parameters -sA and -sF set TCP flags. -sA is a TCP ACK scan, -sF a TCP FIN scan. You may look at how TCP handshakes work and what nmap does in each case.

Guys sorry for the late reply.
I am sick and I was without internet :frowning:

Weā€™d better leave this point out of the way.
If I ever have a break-in, I wonā€™t think about you :wink:
Thank you for your understanding.

They used to say the same about Cisco and the Pentagon :wink:
There is only one secure network hardware in the world: Disconnected from the network :wink:

Stealth

No, I use a VPN for all my activity in my country.

I am not sure yet, but I am starting to suspect false positives due to my fault = incompetent use of nmap.

I tried everything that came to my mind (tools available on the Internet and independent work).
The results were so varied that I was amazed.

Unfortunately, I donā€™t know how to check it. Iā€™m tired of it :frowning:

Then I hope you put your real IP into those web tools and didnā€™t make them test open ports of your VPN provider.