A small start-up company has three computers 1,2 and 3 (blue circles), and is now setting up a network between the computers. Here is a network plan for the company that I made (consulting fee 1000!). The big blue rectangles are the computers and the black smaller rectangles are the NIC (Network interface card). All computers have IP packet forwarding on.

a) A small careless error has crept into the plan. Correct the error! There is only one error and when it is corrected everything is correct in the grid plan.

b) After the correction in a) how many local networks are there in this plan?

The following table may help to answer:

\begin{tabular}{|l|l|} \hline 00000001 & 1 \\ \hline 00000010 & 2 \\ \hline 00000100 & 4 \\ \hline 00001000 & 8 \\ \hline 00010000 & 16 \\ \hline 00100000 & 32 \\ \hline 01000000 & 64 \\ \hline 10000000 & 128 \\ \hline \end{tabular}