Figure is a collection of intermediary devices including a wireless router, a LAN switch, a router, a multilayer switch, and a firewall appliance. Intermediary network devices perform some or all of these functions: Regenerate and retransmit data signals; Maintain information about what pathways exist through the network and internetwork; Notify other devices of errors and communication failures; Direct data along alternate pathways when there is a link failure; Classify and direct messages according to priorities; Permit or deny the flow of data, based on security settings