A method for network address maintenance in a data-over-cable system. The method includes receiving a message containing a first network address, such as an Internet Protocol address, to be stored in a network address table, such as an Address Resolution Protocol table. If the first network address equates to a second network address stored in the network address table, one or more network addresses associated with the second network address are deleted from the network address table. A third network address is then stored in the network address table. The method provides for the removal of stale network addresses, freeing memory space and increasing security in the data-over-cable system.