Method for preventing IP address cheating in dynamic address allocation
Disclosed is a method for preventing IP address cheating in dynamic address allocation.Firstly,check the source MAC address and the source IP address involved in an ARP packet sent from a subscriber terminal,i.e.,detect whether there is a matching item in the legal subscriber address table; if so,process it normally,otherwise discard the ARP packet.In this way,an illegal subscriber cannot access to network through IP address cheating,but a legal subscriber can operate normally and continuously.For a subscriber terminal with a static IP address,a static item table is set in the legal subscriber address by manual configuration.When a new subscriber terminal asks for being allocated an IP address,check whether the IP address to be allocated has been set as a static item; if so,inform the subscriber terminal of applying for another IP address.In this way,it is guaranteed that static IP address having been allocated to a subscriber terminal will not be re-allocated,and it is avoided that the subscriber terminal with legal static IP address cannot access to network normally due to the re-allocation of IP address.