Popular network analysis and visualization tools include Nagios, Zabbix, SolarWinds, and Splunk. Nagios is an open-source tool that provides comprehensive monitoring, alerting, and reporting for network devices, servers, applications, and services. It has various plugins and integrations for data collection and visualization. Zabbix is another open-source tool that offers high-performance monitoring, analysis, and visualization for large-scale and complex networks. SolarWinds is a commercial tool with a suite of products for network performance, configuration, security, and traffic analysis and visualization. It has a user-friendly interface, customizable dashboards, and advanced analytics. Splunk is a commercial tool that specializes in collecting, indexing, and analyzing large volumes of data from various sources. It provides powerful search, visualization, and reporting capabilities as well as machine learning and artificial intelligence features.