This one's weird:
I can't get the Ethernet shield to connect to the Internet through a router.
1.) When I connect the Ethernet shield to a shared Ethernet port on my XP laptop, the Ethernet shield can quickly and reliably get data from a web server out on the Internet. This works fine.
2.) When I connect the Ethernet to a router, the Ethernet Shield cannot connect to the server. If I press the reset button on the Ethernet shield, it will sometimes be able to hit the server one time, then not any more. It is weird that it only works once, then stops. If it didn't work at all, then I would know to keep digging.
3.) I know the router is working, because I can connect a laptop with the same IP, subnet, and gateway I am specifying in the sketch code, and with those settings the laptop can access the server on the Internet just fine through the router.
4.) I can ping the Arduino's Ethernet shield from other local IP addresses on the router's network.
5.) I cannot get the Arduino Ethernet shield to even connect to a server that is on the same subnet (not going through the router).
6.) The weird thing is that when it is connected through my laptop's fake router (shared Internet connection), it works fine.
Is there a difference in the electrical properties of the fake router's Ethernet port and a real router's Ethernet port? Is there a handshaking difference, TCP vs UDP, 10baseT versus 100baseT, protocol difference, or anything like that which might be causing this problem?
Thanks for any pointers at all!