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    I can ping a host that should not exist!

    General pfSense Questions
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    • S
      scilek
      last edited by scilek

      Today, I set up a router for some acquaintance of mine who also happens to be a small business owner. I took it to his place and installed it without a problem. He wants to be able to connect to some assets at his workplace from anywhere he likes. I opened the HTTPS and SSH ports temporarily so that I could finish the rest of the work in the comfort of my house. I got home and connected to the router. I created and OpenVPN server and connected to the router without a problem. Then I started pinging one of the machines on the local network continuously:

      ping 172.16.0.2. -t -w 500
      

      Everything was working fine. So I was happy having set up yet another router. I disconnected from the OpenVPN server and then started closing my open windows. But when I got too the cmd window, I was horrifed! It was still successfully pinging 172.16.0.2! How could that be?

      I checked all my interfaces but none of them was configured to172.16.0.2. Then it occurred to me to use tracert to trace to the host and this was what I got:

      C:\>tracert -d 172.16.0.2
      
      Tracing route to 172.16.0.2 over a maximum of 30 hops
      
       1    <1 ms    <1 ms    <1 ms  192.168.255.1
       2    44 ms    45 ms    44 ms  212.156.201.190
       3    47 ms    48 ms    48 ms  81.212.2.189
       4    48 ms    50 ms    49 ms  81.212.25.136
       5    47 ms    45 ms    44 ms  81.212.218.208
       6    48 ms    46 ms    46 ms  81.212.199.1
       7    55 ms    55 ms    52 ms  212.156.109.137
       8    48 ms    47 ms    47 ms  172.16.0.2
      
      Trace complete.
      
      

      I know this is not an OpenVPN issue, but still I wonder how on earth could that be? One of the first thing I learned from the book was that private IP addresses are not supposed to show up on the Internet. Does this have and explanation or did someone make a really big mistake somewhere? Does anyone have any idea what is going on?

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        Get with your ISP.. I would assume this company

        Turk Telekomunikasyon Anonim Sirketi

        That is who owns the 212.156 address space you list.. And that is your next hop.. And then you come right back around to same address space.

        And that 81.212 is also their space..

        inetnum: 81.212.0.0 - 81.212.255.255
        netname: TTNET
        descr: Turk Telekom A.S.

        So yeah your router will send that traffic to your isp, because hey it just knows it doesn't have a local route - so it sends it to your ISP... your isp should just really drop it, since it should not show its customers any routers to their internal networks, etc. But looks like you bounce around their network and then hit something in their network with that IP..

        Contact them about it.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.7.2, 24.11

        S 1 Reply Last reply Reply Quote 1
        • S
          scilek @johnpoz
          last edited by

          So yeah your router will send that traffic to your isp, because hey it just knows it doesn't have a local route - so it sends it to your ISP... your isp should just really drop it, since it should not show its customers any routers to their internal networks, etc. But looks like you bounce around their network and then hit something in their network with that IP..

          So that is not supposed to happen, right? Someone made a very big mistake somewhere and this is an embarrassing situation for a multi-billion dollar company, right?

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by johnpoz

            Yeah it shouldn't happen no ;) Do large corps make mistakes - sure all the time!

            But keep in mind you are actually connected to "their" network - so they can use rfc1918 space in that network for sure... Look at your dhcp server you get from your isp, quite often this is a rfc1918 IP address..

            An intelligent man is sometimes forced to be drunk to spend time with his fools
            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
            SG-4860 24.11 | Lab VMs 2.7.2, 24.11

            S 1 Reply Last reply Reply Quote 1
            • S
              scilek @johnpoz
              last edited by

              @johnpoz said in I can ping a host that should not exist!:

              Yeah it shouldn't happen no ;) Do large corps make mistakes - sure all the time!

              Well that's a load off my mind! I was beginning to question my networking expertise! I spent hours trying to fix my own PC...

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              • johnpozJ
                johnpoz LAYER 8 Global Moderator
                last edited by

                If in your trace you had bounced around to other networks - then that would be a concern... But you look to just stay in the Turk Telekom network...

                An intelligent man is sometimes forced to be drunk to spend time with his fools
                If you get confused: Listen to the Music Play
                Please don't Chat/PM me for help, unless mod related
                SG-4860 24.11 | Lab VMs 2.7.2, 24.11

                1 Reply Last reply Reply Quote 0
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