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How to block other DHCP server in my network?

peter zaher

Hello,

I'm new to Sophos Community and user.

Today i faced a problem that someone inside my network reset an access point and its default setting enabled DHCP, so all devices get IP from access point.

can anyone help me.



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  • 0

    Peter this an issue that a firewall cannot managed if the network is flat.

    XG can block the dhcp requests if they traverse the firewall (layer 3) but if your computers get an ip from a dhcp in the same LAN you have to use other mechanisms to block rogue dhcp servers (nac for example and training your users).

    Regards

  • 0

    The better network switches can do this.   They can both block unauthorized dhcp servers as well as tracking dhcp assignments to prevent rogues frim using an ip address that has been given to someone else.

    It needs to be done by a device that sees every port, which is your switch.

  • 0 in reply to DouglasFoster

    it was easy to solve in mikrotik just create network bridge serve lan and filter input/output/forward to drop dhcp from specific network/ip

  • 0

    That prevents dhcp from crossing the boundary, but does not prevent a rogue device from misleading a device on the same side of the boundary.  A switch-based solution is what is needed, so there is little incentive for Sophos to nuild the feature into a perimeter device like SG or UTM.