Working principle of ARP virus
Over a period of time, now and in future, ARP cheating virus would always be the “kernel criminal” causing unstable network. The working principle of such kind of virus is to use ARP cache table and the defects. In network, the communication between computers is through MAC address, one computer in the network communicates with other, then it would first convert the other side IP address to the relevant MAC address of the target computer, this conversion process, generally, first starts to looking for from own ARP cache table. If there’s none in own ARP cache table, then broadcasting to the network to obtain. But ARP cache table has the shortage that it has certain lag and easy trust specialities, the ARP broadcasting sent by any computer within the network, the one received would create the relevant relationship between IP and MAC on its own APR cache table, no matter whether it’s correct or not. While ARP virus’s working principle takes advantage of this point to send ARP broadcasting to the network, relating its own MAC address with gateway IP address, then the machines within the network take the infected computer as the gateway, finally leading to the Internet connection failure.
Internet bar Defence
As Internet bar—such a small scale of LAN, as long as there’s one computer infecting ARP cheating virus, then probably all computers within the entire LAN could not connect Internet normally. Therefore, as the Internet supervisor, you must prepare def