Welcome with the same IP address of a default gateway. How to prevent?

Hello

This week, I had a problem in the network. A host has been connected to the network with the same IP address of the gateway by default of this Vlan.

Is there a way to prevent it? I know with 802.11 x I know who done it, but it would avoid the problem to occur.

Is there anyway to force the hosts to use DHCP or something?

It will also prevent an unauthorized on an untrusted interface DHCP server. It provides (on an untrusted interface) only DHCP client messages such as DHCP queries (rejects messages from the DHCP server as DHCP responses) and allows only the source IP address packages he knows the addresses assigned by DHCP. Who is?

Darren

Tags: Cisco Security

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