Just ran into a strange problem.
Up to now I have been powering my project (Mega+Ethernet Shield+1602 LCD+RF receiver) via my laptop USB and the LAN connects without any problems.
The laptop and Ethernet shield are both connected to the same router with DHCP enabled.
Today I tried powering the project from a USB wall-wart.
I tried 2 different USB wall-warts and my phone charger...
USB Wall-wart 1 : 5V DC Rating 1.6 - 2A ; output voltage 4.93V including cable.
USB Wall-wart 2 : 5V DC Rating 2.1A ; output voltage 5.17V including cable.
Samsung Charger : 5V DC Rating 2A ; output voltage 5.2V including cable.
When using the USB wall warts I get make a LAN connection.
I also tried an AC power adapter 12V/2A and powered via the barrel jack.
Again, I simply cannot get a LAN connection.
I can only get a LAN connection when powering the project via the laptop USB.
Anybody have any idea what is going on here?