Beats - Beats is the platform for single-purpose data shippers that is installed as lightweight agents and send data to machines to Logstash or Elasticsearch.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
Riemann - Container Monitoring
tcpdump - tcpdump is a common packet analyzer that runs under the command line.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
SmartSniff - SmartSniff is a packet sniffer that capture TCP/IP packets and display them as sequence of conversations between clients and servers.