Wrong DHCP subnet



  • Hello,

    I have a problem with clients with cable connected. We have a house with cca 100 patch cable installation.

    Few days ago, I setup pfSense with DHCP on LAN as 10.100.100.50-250 and some PCs receive IP from different subnet as 10.10.0.x. Why is that happening?

    We have two 42-port switches and both are managed and set to 10.100.100.5 and 6 as IP and 10.100.100.2 as gateway.

    Why is that happening and how can I find the result of this? Thank you very much for your help!

    Ivan


  • Galactic Empire

    @kdi-isusovci

    Do an ipconfig /all and look what IP address is handing out the wrong subnet.


  • LAYER 8 Global Moderator

    So you setup pfsense as 10.100.100.2/ 24 as its IP??

    Or did you use say a different mask than /24 so dhcp could be larger? like /8 (255.0.0.0)

    If you truely setup pfsense on 10.100.100/24 then its not possible that pfsense would hand out that IP range - and you have another dhcp server on your network.



  • @johnpoz I setup pfsense as 10.100.100.2 /24

    @NogBadTheBad i recieve something like this:

    IP: 10.10.0.213
    mask: 255.255.255.0
    GW: 10.10.0.1

    and that doesn't exist.



  • Sorry, I found the solution. It was one of AP's that I accidentally typo, I setup it's IP as 10.100.0.12 and I needed 10.100.100.12, and also it was DHCP turned on.

    Is there any solution to stop users to connect their AP's and setup it without me? It shows that all internet can crash cuz of that.

    Thanks!


  • LAYER 8 Global Moderator

    You have users connecting rouge AP to your network? Yeah to stop that you would need to use a NAC be it by hand or automatic, etc.



  • @kdi-isusovci said in Wrong DHCP subnet:

    Sorry, I found the solution. It was one of AP's that I accidentally typo, I setup it's IP as 10.100.0.12 and I needed 10.100.100.12, and also it was DHCP turned on.

    Is there any solution to stop users to connect their AP's and setup it without me? It shows that all internet can crash cuz of that.

    Thanks!

    Some managed switches will allow only specified MAC addresses on each port.


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