I often use
FindPath[G, 1, 2, {L}, All]
where $G$ is some graph. This finds all paths of length exactly $L$ edges which run between nodes $1$ and $2$.
In large graphs this is very slow.
One solution is to (I think) use Depth-Limited-Search starting at node $1$, of depth $L$.
I there an efficient way of doing this in Mathematica?