(The enterprise-class Cisco switch GUI management tool, Cisco NetworkAssistant (CNA), is a free tool from Cisco that can be used to equip Cisco equipment such as Catalyst switches, PIX firewalls, IP phones, and wireless access points. CNA support, as long as it is facing small and medium enterprises. CNA provides a lot of features and guides. CNA provides equipment, monitoring, troubleshooting, and protection, through which we can more easily manage network equipment. Set up security management but one thing is that the desktop can be completed, and commands can be completed. To use CNA to connect to a cisco network device, you must first enable the snmp read-only function and the web function (iphttpserver).)