Network device and address learning method thereof

A network device, comprising:

• a first memory unit;
• a second memory unit having a data table and a hashed-address table;
• a programmable logic device electrically connecting to the first memory unit and the second memory unit, and having a fetching module, an address computing module and a registering module, wherein the fetching module fetches an address data string from the first memory unit, the address computing module generates a hashed-address, and the registering module writes the address data string and the hashed-address into the data table and the hashed-address table, respectively,
• a third memory unit, wherein the address data string is recorded in the third memory unit;
• and
• a calculator program executed by a computing unit for respectively reading the address data string and the hashed-address from the data table and the hashed-address table, and writing the address data string into an address of the third memory unit corresponding to the hashed-address
• wherein the second memory unit further has a deletion address table, and the computing unit writes a deletion address into the deletion address table and outputs a deletion instruction to the programmable logic device, and
• wherein the programmable logic device deletes data in an address of the third memory unit corresponding to the deletion address according to the deletion address of the deletion address table.