FTP Arduino issue with ESP8266 - ftp

Question

Trying to do FTP with my router from an ESP8266 WiFi-board and using the Arduino-IDE, I keep getting the following error message:
331 Password required for anonymous.
My code looks like this:
if (client.connect(server, 21)) { // 21 = FTP server
Serial.println(F("Command connected FIRST TIME"));
} else {
Serial.println(F("Command connection failed FIRST TIME"));
}
eRcv();
Serial.println("OUTPUT BUFFER 1");
Serial.println(outBuf);
client.println(F("USER anonymous"));
eRcv();
Serial.println("OUTPUT BUFFER 2");
Serial.println(outBuf);
client.println(F("PASS anonymous"));
eRcv();
Serial.println("OUTPUT BUFFER 3");
Serial.println(outBuf);
client.println(F("SYST"));
eRcv();
Serial.println("OUTPUT BUFFER 4");
Serial.println(outBuf);
client.println(F("Type I"));
eRcv();
My log looks like that:
WiFi connected; IP address: 192.168.178.33
Command connected FIRST TIME
OUTPUT BUFFER 1
220 FRITZ!Box7490 FTP server ready.
OUTPUT BUFFER 2
331 Password required for anonymous.
As you can see, the error message I receive (i.e. err 331) happens already at cmd nr 2 (i.e. "PASS anonymous2).
The router is set to accept an anonymous FTP (that should not be the problem). The router, of course, is set to allow FTP.
I read something about a "passive mode" (client.println(F("PASV"));) but it seems to me that the "PASS anonymous" should go through independent of PASV-mode ore not. Is this correct ?
Are there any other suggestions of what to do here ?
Much appreciated!
P.S. For completion, the FTP-receive (delivering the "outBuf" from the example-code above) looks like this:
//-------------- FTP receive
byte eRcv() {
byte respCode;
byte thisByte;
long StartTimeoutTime = millis();
while (!client.available() && (millis() - StartTimeoutTime < 1000))
{ // wait for answer with 1 second timeout
delay(1);
}
if (millis() - StartTimeoutTime >= 1000)
{
efail();
return 0;
}
respCode = client.peek();
outCount = 0;
while (client.available()) {
thisByte = client.read();
//Serial.write(thisByte);
if (outCount < 127) {
outBuf[outCount] = thisByte;
outCount++;
outBuf[outCount] = 0;
}
}
if (respCode >= '4') {
efail();
return 0;
}
return 1;
} // eRcv()

Answer 1

Anonymous authentication with FTP still requires that you send a username and a password. Traditionally the username is anonymous and an email address is used as a password. Something like user#test.com works fine. Here is a link to RFC 959, File Transfer Protocol.
From here it looks like you might not be waiting long enough for the server to send the 220 message before you send the USER. After you connect, wait for the server to finish sending its welcome message. Then send your USER, wait for the 331, then send your PASS. The server might also be sending multiple strings for the first message. Try logging into the FTP server with the commandline client for your o/s and see exactly what it's sending you, and adjust your code for that.