I have an arduino mega with a W5100 shield running a program that receives UDP packets.
When I connect the W5100 directly to my laptop ethernet port it works perfectly. Receiving all the packets.
When I connect the W5100 instead to a 10/100 switch and the laptop as well the arduino refuses to hold a connection to the switch and does not receive any packets.
- I have tried 2 switches including a brand new one.
- The ethernet cable between the computer and the switch works … the switch holds the connection. My cable tester also shows it is good.
- I have disabled wireless on my laptop so the only connection is the wired one
- when I try to ping the W5100 I get no response. There is also no ARP table entry for it on my laptop
I am out of ideas … any guesses as to what i am doing wrong is appreciated.