Kali Linux ARP Poisoning/Spoofing Attack:
ARP spoofing is a type of attack in which a malicious actor sends falsified ARP (Address Resolution Protocol) messages over a local area network. This results in the linking of an attacker’s MAC address with the IP address of a legitimate computer or server on the network.
Kali Linux GNS3
A CAM overflow attack occurs when an attacker connects to a single or multiple switch ports and then runs a tool that mimics the existence of thousands of random MAC addresses on those switch ports. The switch enters these into the CAM table, and eventually the CAM table fills to capacity. When a switch is in this state, no more new MAC addresses can be learned; therefore, the switch starts to flood any traffic from new hosts out of all ports on the switch.
A CAM overflow attack turns a switch into a hub, which enables the attacker to eavesdrop on a conversation and perform man-in-the-middle attacks.
Yes it is bad and is a form of attack. DHCP spoofing occurs when an attacker attempts to respond to DHCP requests and trying to list themselves (spoofs) as the default gateway or DNS server, hence, initiating a man in the middle attack.
It is a really bad attack because the malicious DHCP server can send you to a fake bank website and steal your credentials and all that CASH MONEY