Leshan Giant Buddha, Sichuan, China (© www.anotherdayattheoffice.org/Getty Images)

Using grid lines is a flexible and powerful way to place your elements on a grid, but, when looking at the code, it might be a bit hard to visualize.

Harbor seals at Robert Moses State Park, Long Island, New York (© Vicki Jauron, Babylon and Beyond Photography/Getty Images)

The Neighbor Discovery (ND) protocol is a critical component of the IPv6 architecture. The protocol uses multicast in many messages. It