I am trying to send over my code to my Arduino Ethernet board via the Adafruit FTDI friend. I am using the 1.0.4 version of the IDE and have the following settings:

Tools -> Board -> Arduino Ethernet Tools -> Serial Port -> COM 3

The sketch is sent over to the board without problems or errors... however I am unable to see the IP of the board when i check my "attached devices" in my routers settings menu.

Here is a snip of the code I used:

  byte ip[] = { 192, 168, 9, 199 };   //Manual setup only
  byte gateway[] = { 192, 168, 9, 1 }; //Manual setup only
  byte subnet[] = { 255, 255, 255, 0 }; //Manual setup only

  // if need to change the MAC address (Very Rare)
  byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

  EthernetServer server = EthernetServer(199); //port 199

void setup(){

  //Pins 10,11,12 & 13 are used by the ethernet shield

  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);

  Ethernet.begin(mac, ip, gateway, subnet); //for manual setup



Here is a screen shot of the router settings:

enter image description here

And this is my Arduino ethernet hookup:

enter image description here

What could I be missing?

  • \$\begingroup\$ I've seen some routers where the attached devices list is only a list of devices that have requested a DHCP address. Does it appear on the list / work if you use the commented out Ethernet.begin(mac) line? \$\endgroup\$
    – PeterJ
    Mar 14, 2013 at 1:00
  • \$\begingroup\$ Try pinging the IP you're specifying in your code. Open a command-prompt window, and ping <ip here>. For example: ping \$\endgroup\$ Mar 14, 2013 at 7:05

2 Answers 2


On some routers the attached devices list only contains a list of devices that have requested a DHCP address. Try the following change to go back to using a DHCP address rather than a manual setup:

//Ethernet.begin(mac, ip, gateway, subnet); //for manual setup

Most routers only show devices that have been granted a DHCP lease and since your Arduino has a static IP-address it won't show. You can see the device on your PC once you have contacted it at least once throught the ARP-table:

Here is an example ARP-table (Linux, but Windows is similar):

€ arp -a
? ( at c8:60:00:3b:a8:7e [ether] on eth0
? ( at bc:05:43:e7:36:92 [ether] on eth0
? ( at 08:00:27:a6:a2:e7 [ether] on eth0

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