Ethernet Sield 2 stopped answering web requests

Projects Programming
1

My Ethernet shield 2 on a Arduino uno r3 ran for about a week and then would not answer web requests.
I removed power to it and then restored power and it resumed it's normal function.

How might I stop this from happening in the future?

2

My guess - a variable eventually overflows, or the board runs out of memory, or an array goes out of bounds.

Does it always go the same time before malfunctioning?

Show us the sketch.

3

thanks for your reply.
For now, I am thinking to have the unit do a hard reset periodically perhaps once a day.
Please suggest how to do this.

4

Is your shield exposed to the internet? Maybe you are running out of sockets? Add this to your sketch and call it when you think necessary. I would start out calling it after every request. This was written for the w5100, and I do not have a w5500 to test the code with. If you are running out of sockets due to port scanners, resetting may not be practical.

#include <utility/w5500.h>
byte socketStat[MAX_SOCK_NUM];

void ShowSockStatus()
{
  for (int i = 0; i < MAX_SOCK_NUM; i++) {
    Serial.print(F("Socket#"));
    Serial.print(i);
    uint8_t s = W5500.readSnSR(i);
    socketStat[i] = s;
    Serial.print(F(":0x"));
    Serial.print(s,16);
    Serial.print(F(" "));
    Serial.print(W5500.readSnPORT(i));
    Serial.print(F(" D:"));
    uint8_t dip[4];
    W5500.readSnDIPR(i, dip);
    for (int j=0; j<4; j++) {
      Serial.print(dip[j],10);
      if (j<3) Serial.print(".");
    }
    Serial.print(F("("));
    Serial.print(W5500.readSnDPORT(i));
    Serial.println(F(")"));
  }
}

edit: A status list:
0x0 = available
0x14 = waiting for a connection
0x17 = connected
0x1C = connected waiting for close
0x22 = UDP