NokiaNetworkVoyager·Chapter4 139 3. In the Mask Length field, type the mask length (number of bits) and then click Apply. (The mask length is the prefix length that matches the IP address to form an aggregate to a single routing table entry. By default, the aggregate route is on.) 4. Scroll through the New Contributing protocol list, click the protocol to use for the new aggregate route, and then click Apply. 5. (Optional) If you want to specify a prefix, in the New Contributing Route From Protocol field type the IP address and then click Apply. 6. To make your changes permanent, click Save. t ip You can also remove aggregate routes on the Route Aggregation page. In the table for the aggregate route, click Off and then click Apply.