Connected components
A connected component of an undirected graph is a set of nodes such that for any pair of nodes u and v in the set, there is a path from u to v.
In the Normalized Laplacian Spectrum, the multiplicity of eigenvalue 0 is equal to the number of connected components of G.
The multiplicity of eigenvalue 0 in CAIDA is almost twice as the one in Route Views.
The graph indicates that there are more connected components in the graph of CAIDA.