I am currently doing a project in which I need to connect using an ethernet shield to get time. My problem is very strange... I tested the system at home and connected this system to my internet modem and it worked perfectly.... Then last week I connected my system on another router and it was working fine. Then there wasa a power cut in electric domestic supply and I cannot connect again to the DHCP. I tried many different ways but still it is not connecting. I took the arduino with the shield back home and it is still working good at home... Does anyone know if there could be any setting that could be affected from the router due to the power cut? if yes, how could i fix the problem?
Stefan_28:
Does anyone know if there could be any setting that could be affected from the router due to the power cut? if yes, how could i fix the problem?
DHCP is a really simple protocol.
The DHCP server settings need to be correct, of course.
The server must have an address pool, to serve out.
The pool must contain addresses which have not been leased out.
The server should not be blocking the client MAC address.
The server must be enabled.
There should be no other DHCP servers active on the segment.
You need to check all those conditions are still true. Even if you think nothing was changed, it is possible some configuration change was waiting for a reboot to be applied.
When the power resumes after a power cut, it often causes a power surge, as all the devices in the building try to power up at the same time. Such power surges present quite a risk to routers and switches; often the cause of blown power circuits and ethernet transceivers. A damaged Ethernet transceiver could cause the DHCP issue you are seeing. You could carry out a swap test, try a different device on the same port, try your device on a different port, try different cables in both cases. A swap test is not conclusive but isolate the fault or provide a strong indication.