hi I have been told VLANs can help mitigate ARP poisoning because they can be configured with different broadcast domains. and arp works using a simple broadcast domain. can someone explain how the VLAN achieves this ?
When you configure a VLAN on a local network it's as if you have differents locals networks between your hosts. So if you sniff the traffic on a particular VLAN you will see only the hosts which are conected on this VLAN and not the others hosts of your network. On the switch which manage VLAN you will have a ARP table per VLAN.
Moreover, you can use the privates VLANs to improve your local security.