NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.

Forum Discussion

shiftctrl's avatar
shiftctrl
Aspirant
Aug 02, 2019
Solved

NightHawk R7800 Router is Assigned two IPs

Hi All,

 

I just ran an nmap scan of a network and noticed the router is assigned two IPs (10.0.0.1 and 10.0.32.1)

Scanning open ports on 10.0.0.1 shows there a couple extra ports open compared to 10.0.32.1.

 

Anybody know what's going on here?

  • Which of the two addresses does fit into your LAN TCP/IP subnet? Post a screenshot of the Advanced home - in case that IP does show up. Here the Nighthawk is connected to a WWAN (LTE) mobile provider, assigning RFC1918 addresses (yes, nowadays we can consider this as abuse of these IP addresses - but I'm not interested to hunt Swisscom):

     

     

    The other suspicion is that the other IP does belong to the OpenVPN related tun0 interface - that's the IP used for a many2one NAT for OpenVPN clients accessing the router via the NATed tun(not the bridged tap). Unfortuantely, this IP is nowhere visible in the Nighthawk Web UI. Different LAN subnet here than on your router - but you are a Linux person and get the idea:


    This address is also accessible from the LAN, e.g. by  using a Web browser:

     

     

    For your comparison:


    # nmap 192.168.10.254

    Starting Nmap 7.70 ( https://nmap.org ) at 2019-08-06 11:54 Mitteleuropõische Sommerzeit
    Nmap scan report for 192.168.10.254
    Host is up (0.0027s latency).
    Not shown: 983 closed ports
    PORT STATE SERVICE
    21/tcp open ftp
    23/tcp open telnet
    53/tcp open domain
    80/tcp open http
    139/tcp open netbios-ssn
    443/tcp open https
    445/tcp open microsoft-ds
    548/tcp open afp
    631/tcp open ipp
    3333/tcp open dec-notes
    5555/tcp open freeciv
    8081/tcp open blackice-icecap
    8200/tcp open trivnet1
    10000/tcp open snet-sensor-mgmt
    20005/tcp filtered btx
    49152/tcp open unknown
    49153/tcp open unknown
    MAC Address: A0:04:60:xx:xx:xx (Netgear)

    Nmap done: 1 IP address (1 host up) scanned in 4.59 seconds


    # nmap 192.168.11.1
    Starting Nmap 7.70 ( https://nmap.org ) at 2019-08-06 11:54 Mitteleuropõische Sommerzeit
    Nmap scan report for 192.168.11.1
    Host is up (0.0027s latency).
    Not shown: 987 closed ports
    PORT STATE SERVICE
    21/tcp open ftp
    53/tcp open domain
    80/tcp open http
    139/tcp open netbios-ssn
    443/tcp open https
    445/tcp open microsoft-ds
    548/tcp open afp
    631/tcp open ipp
    3333/tcp open dec-notes
    5555/tcp open freeciv
    8081/tcp open blackice-icecap
    8200/tcp open trivnet1
    20005/tcp filtered btx

    Nmap done: 1 IP address (1 host up) scanned in 4.89 seconds

     

12 Replies

  • michaelkenward's avatar
    michaelkenward
    Guru - Experienced User

    Those IP addresses hint at the presence of a second router on your network.

    • shiftctrl's avatar
      shiftctrl
      Aspirant

      Yeah, that's what I initally thought - the only problem is that, the IP leads back to the gateway (same admin credentials, settings, etc..)

       

      So when I go to 10.0.32.1, it takes me to same admin console with all the same settings as my 10.0.0.1 console.

       

      Even if somone is spoofing my network, then how did they get my admin creds and why leave it with the same user/pass?

       

       

      • michaelkenward's avatar
        michaelkenward
        Guru - Experienced User

        shiftctrl wrote:

         

        Even if somone is spoofing my network, then how did they get my admin creds and why leave it with the same user/pass?

         


        What evidence do you have that this might be happening?

         

        Be a sport, tell us what the modem is in front of your router. Then we can begin to see if the first theory is, as a suspect, a more likely explanation.

         

        It is all too easy to get sucked into complicated theories and interpretations when the answer is staring you in the face.

         

         

         

  • Wondering if you have a PROXY set up? If on Windows you can see it this way:

     

    1. Select the “Start” button, then type “cmd“.
    2. Right-click “Command Prompt“, then choose “Run as Administrator“.
    3. Type “netsh winhttp show proxy“, then press “Enter“.

     

    Does this happen on ALL devices you can use a Browser on?

    • shiftctrl's avatar
      shiftctrl
      Aspirant

      Negative, no proxy. I primarily use Linux, nevertheless, I can access the router from both IPs on all devices in the building (including cellphones, tablets, laptops, etc..)

      • schumaku's avatar
        schumaku
        Guru - Experienced User

        Which of the two addresses does fit into your LAN TCP/IP subnet? Post a screenshot of the Advanced home - in case that IP does show up. Here the Nighthawk is connected to a WWAN (LTE) mobile provider, assigning RFC1918 addresses (yes, nowadays we can consider this as abuse of these IP addresses - but I'm not interested to hunt Swisscom):

         

         

        The other suspicion is that the other IP does belong to the OpenVPN related tun0 interface - that's the IP used for a many2one NAT for OpenVPN clients accessing the router via the NATed tun(not the bridged tap). Unfortuantely, this IP is nowhere visible in the Nighthawk Web UI. Different LAN subnet here than on your router - but you are a Linux person and get the idea:


        This address is also accessible from the LAN, e.g. by  using a Web browser:

         

         

        For your comparison:


        # nmap 192.168.10.254

        Starting Nmap 7.70 ( https://nmap.org ) at 2019-08-06 11:54 Mitteleuropõische Sommerzeit
        Nmap scan report for 192.168.10.254
        Host is up (0.0027s latency).
        Not shown: 983 closed ports
        PORT STATE SERVICE
        21/tcp open ftp
        23/tcp open telnet
        53/tcp open domain
        80/tcp open http
        139/tcp open netbios-ssn
        443/tcp open https
        445/tcp open microsoft-ds
        548/tcp open afp
        631/tcp open ipp
        3333/tcp open dec-notes
        5555/tcp open freeciv
        8081/tcp open blackice-icecap
        8200/tcp open trivnet1
        10000/tcp open snet-sensor-mgmt
        20005/tcp filtered btx
        49152/tcp open unknown
        49153/tcp open unknown
        MAC Address: A0:04:60:xx:xx:xx (Netgear)

        Nmap done: 1 IP address (1 host up) scanned in 4.59 seconds


        # nmap 192.168.11.1
        Starting Nmap 7.70 ( https://nmap.org ) at 2019-08-06 11:54 Mitteleuropõische Sommerzeit
        Nmap scan report for 192.168.11.1
        Host is up (0.0027s latency).
        Not shown: 987 closed ports
        PORT STATE SERVICE
        21/tcp open ftp
        53/tcp open domain
        80/tcp open http
        139/tcp open netbios-ssn
        443/tcp open https
        445/tcp open microsoft-ds
        548/tcp open afp
        631/tcp open ipp
        3333/tcp open dec-notes
        5555/tcp open freeciv
        8081/tcp open blackice-icecap
        8200/tcp open trivnet1
        20005/tcp filtered btx

        Nmap done: 1 IP address (1 host up) scanned in 4.89 seconds