New
#11
problem solved!
I feel so happy right now (I am sure you know the feeling after tinkering for several hours). The solution was to change the MAC address of the NIC.
If you have any idea as to why this is the solution or what is it exactly that caused the problem in the first place i'd be very happy to know. BTW the NIC already had a legitimate MAC address, not something like 000000000000.