Wireshark
Wireshark is a free network protocol analyzer. It is the de facto standard when it comes to packet data analysis. It can be used to investigate the communication traffic by inserting a PC into the network. The utility can be used to see all traffic, or can be configured to filter traffic for a defined subset of the communication partners. Filters can also be used to track specific protocols and therefore help the designer confirm their firmware is behaving as expected.
Download and training can be found at www.wireshark.org.
Tools Used to Verify Basic Connectivity
tracert:
Trace Route displays the route packets take when moving between your computer and a particular web site or IP address.
ping:
Ping returns the IP address of a web site and the round trip time to receive a reply.
ipconfig:
ipconfig returns all Ethernet and WLAN adaptor information for the host. Using the “/all” option will also show MAC addresses.
iperf:
"iperf” is a free network analysis tool. It generates TCP or UDP traffic and measures performance including packet loss and throughput. “jperf” is a GUI front end for iperf.