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lessexciting's avatar
lessexciting
Joining in
10 months ago

Hub 3 - rogue DHCP in modem mode

Hello. 

I’m having trouble with a rogue dhcp server on my network and I think it’s originating from my hub3, that is supposed to be in modem mode. 

i have devices being assigned IP’s in the range 192.168.0.x. My Edge router that should be the only dhcp server on the network is at 192.168.1.1.

I have had the hub replaced due to a consistent red light indicating an issue, but this dhcp server problem persists. 

 I’ve considered whether there might be another device on the network responsible for this rogue dhcp but given the IP address it must be the hub3, right? I’ve looked up trying to identify a dhcp server via a MAC address but I haven’t had much luck.

Any insight anyone could provide would be most welcome.

 Thanks

6 Replies

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  • Client62's avatar
    Client62
    Alessandro Volta
    10 months ago

    Hub 3 in modem mode has magenta panel light. One man's magenta is another man's red.
    Check the Hub 3 Temperature from the Hub 3 menu >> Network diagnostic tool

    Is the Edge Router is in router or access point mode ?

    Is the Edge Router connected via a WAN or LAN port to the Hub 3 ?

    What are the DNS IPs and Gateway IP of the 192.168.0.xxx device ?

    Does the 192.168.0.xxx device gain internet access ?
    If yes who is the ISP ?  https://whatismyipaddress.com/

    • lessexciting's avatar
      lessexciting
      Joining in
      10 months ago

      Thanks for your reply.

      I'm confident the light is magenta. I'm struggling to find the network diagnostic tool in the router interface, but i'm confident it's not overheating. It's not boxed in in any way. 

      I can't find any info about access point mode for the Edge Router and therefore i can only assume it's in router mode.

      The Edge router connects to the hub3 via eth0, which a search tells me is the WAN port for Edge routers. 

      In terms of the DNS and gateway addresses for devices that have received a 192.168.0.x IP, one of the issues i have is that i can't reliably get a device to be assigned to the 'rogue' dhcp server, and therefore it's difficult to give you those details, but i'm sure that the router address / gateway was given as 192.168.0.1. I'm unsure of the DNS. 

      In terms of internet access, devices with 192.168.0.x addresses do not gain internet access. 

      Thanks again.

  • legacy1's avatar
    legacy1
    Alessandro Volta
    10 months ago

    you have HomePlug - Network Via Mains?

    DHCP for 192.168.0.0/24 can not be given from the hub over the WAN port of Edge router to your LAN

    • lessexciting's avatar
      lessexciting
      Joining in
      10 months ago

      Thanks for your help.

      I do use powerline adapters but i'm not sure they have a part to play in this, as the bad address assignment happens to devices connected to the wireless access point that's directly connected to the Edge router, as well as the access point connected via powerline adapters. 

      This morning I restarted the wireless access point that does feed through a powerline adapter and that access point itself was given a 192.168.0.x address, stopping any connected devices from accessing the internet. 

      If i understand you correctly, are you suggesting that it's not possible for the hub3 to actually advertise dhcp via the Edge router, and therefore there must be another explanation to these issues? 

      Many thanks

      • Tudor's avatar
        Tudor
        Very Insightful Person
        10 months ago

        If the Hub3 is correctly in modem mode it cannot field any DHCP requests at all as the DHCP server is not running on the hub. You can ascertain this by disconnecting everything from the hub in modem mode except for one hard wired device. On this device try pinging 192.168.0.1, it should fail, proving the hub is correctly in modem mode.

  • legacy1's avatar
    legacy1
    Alessandro Volta
    10 months ago

    Yup it powerline adapters you been connecting next door

    it not possible for the hub3 to actually given DHCP other then 192.168.100.x on bootup only the WAN IP through the hub is possible.