Static Mapping and IP conflict.



  • I am running 2.2.6 connected as follows: ISP Modem > PFSense >Unmanaged Switch > Wifi Router and Clients

    I used PFsense to map a static IP to my Macbook. It was working fine, until my Amazon FireTV connected, and somehow got assigned the same IP as the Macbook. The Wifi Router is a Netgear, and the DHCP server is turned off. The FireTV doesn't have a static IP. What assigned the FireTV the same IP as my Macbook if the Macbook has been mapped to that IP, and there is no other DHCP server on the network?



  • If your FireTV has picked up a DHCP address, then obviously there is a DCHP server operating on your network, whether you're aware of it or not. Why not put a Windows/Linux machine on your network with the network settings set to dynamic and see if it picks up an address? You only have to then run an 'ipconfig /all' to find out the IP of the DHCP server handing out the addresses.


  • LAYER 8 Global Moderator

    here is a nice little tool to just look for dhcp servers..

    https://github.com/CyberShadow/dhcptest

    you send out a discover packet and see what you get back..

    Since static mappings with pfsense are outside the scope.. It would seem impossible for pfsense to have handed out that duplicate - so that points to a different dhcp server..  To be honest a client getting a dupe should be pretty hard since many dhcp server and clients look to see if anyone has the IP before they actually use it or hand it out.




  • Something goofy happened. I was using the Macbook with an IP mapped to .29, walked away for 30 minutes, came back and received error message "another device on the network has the same IP". Logged into the PFsense GUI and sure enough the Fire was assigned .29….


  • LAYER 8 Netgate

    ISC dhcpd will not do that. You likely have another DHCP server on your network.



  • @oguruma:

    Something goofy happened. I was using the Macbook with an IP mapped to .29, walked away for 30 minutes, came back and received error message "another device on the network has the same IP". Logged into the PFsense GUI and sure enough the Fire was assigned .29….

    Well, you've had a couple of suggestions already about what to do. Given them a try and see how you get on.


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