• Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Search
  • Register
  • Login
Netgate Discussion Forum
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Search
  • Register
  • Login

I can ping a host that should not exist!

Scheduled Pinned Locked Moved General pfSense Questions
6 Posts 2 Posters 842 Views 2 Watching
Loading More Posts
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • S Offline
    scilek
    last edited by scilek Mar 19, 2020, 7:47 PM Mar 19, 2020, 7:45 PM

    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?

    1 Reply Last reply Reply Quote 0
    • J Offline
      johnpoz LAYER 8 Global Moderator
      last edited by Mar 19, 2020, 7:52 PM

      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 25.07.1 | Lab VMs 2.8.1, 25.07.1

      S 1 Reply Last reply Mar 19, 2020, 8:00 PM Reply Quote 1
      • S Offline
        scilek @johnpoz
        last edited by Mar 19, 2020, 8:00 PM

        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?

        1 Reply Last reply Reply Quote 0
        • J Offline
          johnpoz LAYER 8 Global Moderator
          last edited by johnpoz Mar 19, 2020, 8:05 PM Mar 19, 2020, 8:03 PM

          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 25.07.1 | Lab VMs 2.8.1, 25.07.1

          S 1 Reply Last reply Mar 19, 2020, 8:06 PM Reply Quote 1
          • S Offline
            scilek @johnpoz
            last edited by Mar 19, 2020, 8:06 PM

            @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...

            1 Reply Last reply Reply Quote 0
            • J Offline
              johnpoz LAYER 8 Global Moderator
              last edited by Mar 19, 2020, 8:07 PM

              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 25.07.1 | Lab VMs 2.8.1, 25.07.1

              1 Reply Last reply Reply Quote 0
              1 out of 6
              • First post
                1/6
                Last post
              Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.
                This community forum collects and processes your personal information.
                consent.not_received