|  |  | Many tools are available to enhance the security of networks. The firewall is not the end-all solution; it is only one security measure. Network analyzers (packet sniffers) define the data that crosses networks daily. Network scanners can describe devices attached to networks. A network scanner can define the type of operating system a host is running. Vulnerability assessment tools determine weak points in the network and whether the firewall is performing adequately. Password-cracking tools break an encrypted password database, ensuring that users are utilizing strong passwords.