Ethernet ports don't have up addresses, they have a Mac address which is globally unique and assigned at the factory. When a computer wants to talk on a lan, it has an ip address and uses Arp to look up the mac, at a hardware level the packet is sent to the Mac address; Ethernet switches only know the Mac address.
By tampering with Apr you can make network traffic go the wrong way which sets the stage for all kinds of abuse.
Arp is the address resolution protocol.
Ethernet ports don't have up addresses, they have a Mac address which is globally unique and assigned at the factory. When a computer wants to talk on a lan, it has an ip address and uses Arp to look up the mac, at a hardware level the packet is sent to the Mac address; Ethernet switches only know the Mac address.
By tampering with Apr you can make network traffic go the wrong way which sets the stage for all kinds of abuse.