As a TCP server, it stands by until being connected by a TCP client. As TCP states, handshakes would be done before connection actually established between client and server(for more details please refer to Transmission Control Protocol)
Like what an internet browser does, web address(for example www.google.com) or IP address(126.96.36.199) is used to request for information from its server. Instead, these sample code allows you to get the IP address of the corresponding web address through DNS server only.
W5500 allows us to use it as an HTTP server to achieve various goals. W5500EVB stores HTML data in its database(memory), and return the requested data to client, displaying the HTML as a website through web browser.
“Ping” is an important function in Networking. It is a function to see if the connectivity is alright, which is an essential tool for debugging. It is under Internet Control Management Protocol (ICMP), no wonder why it is important for debugging.
IoT devices are often working remotely. Therefore, power efficiency is always one of the considerations when developing an IoT device. W5500, like other chips do, has power mode functions so that users can choose whatever mode they want for their own sake.
By utilizing W5500, users do not have to plug their product into the computer every time they want to update the program, instead they can remotely do the update. Apart from how TCP and UDP works, which you must have already learned at this point, you need knowledge about how to manipulate the data in the memory of your MCU.
Whenever there is a transportation of packet through network, both MAC and IP address are required. Nevertheless, for the first time you are going to send a packet to a desired host, you most probably do not have its MAC address. ARP is then a way for you to get the MAC address you want.
Just like other microcontrollers, W5500 has its own pins for interrupt. Using interrupt instead of polling with W5500 allows users to free the socket from having it connected continuously, even there would be no data received for a while. In other words, you can use interrupt to achieve many more sockets than W5500 has (Max 8 sockets for W5500).
SNMP (Simple Network Management Protocol) consists of an application layer protocol and database schema. It used to control and monitor network devices with different manufacturers and models. With the rapid development of IoT (interest of things) technology, network management becomes a critical issue. SNMP provides a solution to monitor these network devices.