|  | 11.4 | Link-State Routing
| 11.4.4 | Two link-state concerns
There are two link-state concerns - processing and memory requirements, and bandwidth requirements. Processing and memory requirements Running link-state routing protocols in most situations requires that routers use more memory and perform more processing than distance-vector routing protocols. Network administrators must ensure that the routers they select are capable of providing these necessary resources. Routers keep track of all other routers in a group and the networks that they can each reach directly. For link-state routing, their memory must be able to hold information from various databases, the topology tree, and the routing table. Using Dijkstra's algorithm to compute the SPF requires a processing task proportional to the number of links in the internetwork, multiplied by the number of routers in the internetwork. Bandwidth requirements Another cause for concern involves the bandwidth that must be consumed for initial link-state packet flooding. During the initial discovery process, all routers using link-state routing protocols send LSA packets to all other routers. This action floods the internetwork as routers make their en masse demand for bandwidth, and temporarily reduce the bandwidth available for routed traffic that carries user data. After this initial flooding, link-state routing protocols generally require only minimal bandwidth to send infrequent or event-triggered LSA packets that reflect topology changes.