No warning when setting up an IP conflict



  • When I setup an IP Adress conflict by assigning the same IP to multiple different devices on the same Interface in the DHCP Server there is no warning about that. It happened to me 2 times already, is there an Option to enable a warning when I am about to do that? There are only a few scenarios where this is actually wanted, so by default there should be a warning (and it could even select the next available IP) and if someone really wants to do that, they can disable that warning. Maybe I have just not found that option yet, but i‘d love to hear about you guys‘s opinion aswell before I make a Feature request out of this.


  • LAYER 8 Rebel Alliance

    Make a documentation of your network to avoid conflics.
    Even with such a warning you can still create conflicts when the other device is turned off.

    -Rico



  • The documentation is my static address assignment table in pfsense. Even if the device is offline pfsense still knows about it as there is an entry in it static address assignment table, but it still let's me do it. There's only an error message if the MAC addresses are the same.

    The only scenario where this might be wanted is if there are 2 devices that are never on at the same time to save an IP address.....


  • LAYER 8 Netgate

    Can only prevent so much foot-shooting with code.

    Don't set up conflicting networks.



  • It's not a conflicting network, it's on the same interface! And it will just let me assign the same IP to multiple devices, and those devices will get that IP from the server and it will cause issues then as you have a conflict then. If it wouldn't be on the same network or a static IP that hasn't been acquired by DHCP would conflict that's clearly something that can't be prevented in software, but making the DHCP server give 2 devices on the same network the same address shouldn't happen without a warning that you might be doing something wrong there.


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