hi!

There is a bug in the Arduino 0013 Ethernet library.

A second connection to the same server doesn´t work. Only the first connection will work. Exact same code works fine in Arduino 0012.
I need the new float feature in the 0013 Ethernet libarary. So it would be nice if you fix it or release a work around. Thanks.

MFV

I am having the same issue.  It hangs the Arduino completely on the second connection attempt.  Here is the code I am using:

Code:

#include <Ethernet.h>

// network configuration.  gateway and subnet are optional.
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 192, 168, 1, 178 };
byte server[] = { 192, 168, 1, 54 };

Client client(server, 13000);

long timerX = 31000;

void setup()
{
  // initialize the ethernet device
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  Serial.println("Ethernet ChatServer Online");
}

void loop()
{
  if (client.available())
  {
    while (client.available())
    {
      char c = client.read();
      Serial.print(c);
    }
  }
  
  long currentTime = millis();

  if (abs(currentTime - timerX) > 10000)
  {
    Serial.println(timerX);
    if (client.connect())
    {
      client.println("Arduino Rocks!");
      timerX = millis();
      Serial.println("Client Message Sent");
    }
  }
} 

Here is what I get back in the serial monitor:
Code:

Ethernet ChatServer Online

31000

Client Message Sent

ARDUINO ROCKS!

647 

I have a simple tcplistener running on my computer that echoes back whatever it receives.  As you can see it works on the first attempt and is about to attempt again after the 647.  But, that is it, nothing happens after that.  If the connect failed it should keep spitting out 647 until it connects because that value is not reset until a connection is made.  So it seems the Arduino simply hangs at that point.

I made the change, but it still hangs on the second connection.

Hi,

Tested it with the code above, but modified to use the standard "echo" service on port 7. Got a few TCP connection listed as open before the code somehow went into a "loop" writing the number "31075" to the serial console...

inetutils 15945        root    3u  IPv6  55938       TCP lupus.local:echo->10.0.0.177:1030 (ESTABLISHED)
inetutils 15946        root    3u  IPv6  55939       TCP lupus.local:echo->10.0.0.177:1031 (ESTABLISHED)
inetutils 16067        root    3u  IPv6  56394       TCP lupus.local:echo->10.0.0.177:1027 (ESTABLISHED)
inetutils 16068        root    3u  IPv6  56395       TCP lupus.local:echo->10.0.0.177:1028 (ESTABLISHED)
inetutils 16069        root    3u  IPv6  56396       TCP lupus.local:echo->10.0.0.177:1029 (ESTABLISHED)
inetutils 16072        root    3u  IPv6  56529       TCP lupus.local:echo->10.0.0.177:1025 (ESTABLISHED)
inetutils 16074        root    3u  IPv6  56567       TCP lupus.local:echo->10.0.0.177:1026 (ESTABLISHED)

regards,

Hi,

Tested it with the original Client.cpp file and it do block, as originally reported by MFV.

Thinking of it it is not so strange as it with the line

  socket(_sock, Sn_MR_TCP, _port, 1024 + _srcport);

will create a new 5-tuple for the IP connection that is identical to the previous one. And that will not work. Changing the line into

  socket(_sock, Sn_MR_TCP, 1024 + _srcport, 0);

will on the other hand create a new unique 5-tuple (the originating port number changes) for the IP connection like it should do.

regards,

Hello again,

ich changed
 socket(_sock, Sn_MR_TCP, _port, 1024 + _srcport);
into
 socket(_sock, Sn_MR_TCP, 1024 + _srcport, 0);
in hardware/libraries/Ethernet /Client.cpp

recompile my sketch but Arduino still send one request and stop then. Hm...

Fin, it works.
Great job. Thanks.

I made those changes but I think I have another problem, after 5 connections (one after another ... not at the same time) ... the arduino refuses any connection for about a minute ? Is there something I should be calling to free up those connections, besides client.stop(); ?