My Netduino Plus 2 (v126.96.36.199 Jan 26 2013) is working at home with networking, then I bring it to work today and network time protocol requests are failing. I do some digging, and the DNS entry is my home router, not my work DNS. DHCP is enabled, and the other parameters are okay (IP, subnet, router, etc.)
So I used WireShark to capture the relevant DHCP packets. Netduino should be requesting DNS options but is not. The BOOTP option 55 only includes Subnet Mask, Router, and Broadcast Address. It should also include DNS as a requested parameter. The DHCP server at home supplies the DNS entry anyways, but the DHCP server at work appears to be strictly complying with the parameter request and doesn't supply the DNS entry if not requested.
Option: (55) Parameter Request List Length: 3 Parameter Request List Item: (1) Subnet Mask Parameter Request List Item: (3) Router Parameter Request List Item: (28) Broadcast Address
There should be at least one more item included:
Parameter Request List Item: (6) Domain Name Server
Relevant packet dump from work is attached.