On a normal Ethernet there is nothing that can prevent devices on the network to interfere with each other. Tools like DHCP can assist in preventing accidental conflicts if used correctly, but malicious or misconfigured hosts can still cause problems.
Some things that are common:
- Conflicting addresses (two or more MAC addresses that claim to have the same IP address in ARP or ND)
- ARP or ND spoofing (someone intentionally pretending to be someone else)
- Rogue RAs (someone sending IPv6 Router Advertisements when they shouldn't)
- Rogue DHCPv4 or DHCPv6 servers (DHCP servers that shouldn't be there)
As ethernet is a broadcast medium everybody can broadcast anything they want, unless special actions are taken. For such special actions you need equipment that can implement them. This means you need enterprise-grade ethernet switches, wireless access points etc. The measures they can take are e.g. to filter out unwanted RA and DHCP packets, make sure that a system only sends packets with a source address that has been assigned by DHCP (this requires DHCP snooping on the switch) and protections against ARP and ND highjacking.
Such security features are only available on professional equipment, so don't expect them on consumer or SME devices or low-budget enterprise gear.