Topology: Source S and Destination D are connected via two intermediate routers R1 and R2:

  S ---- R1 ---- R2 ---- D

There are 3 links (hops) total: S-R1, R1-R2, R2-D.

Layer visit count

Data Link Layer — visited once per link/hop the packet crosses, because a new frame (with fresh MAC addressing) must be created for each physical link:

S -> R1 : 1 visit (frame created at S, processed at R1)
R1 -> R2: 1 visit (new frame created at R1, processed at R2)
R2 -> D : 1 visit (new frame created at R2, processed at D)

Total Data Link layer visits = 3 (once per link)

Network Layer — visited once at each node the packet passes through (source, every intermediate router, and destination), since routing/forwarding decisions (or final delivery) happen at the Network layer at every node:

At S : Network layer processes the packet once (originates it)
At R1: Network layer processes it once (routing decision)
At R2: Network layer processes it once (routing decision)
At D : Network layer processes it once (final delivery, passed up to Transport layer)

Total Network layer visits = 4 (once per node: S, R1, R2, D)

Summary: For a path with k intermediate routers (here k=2), a packet visits the Network layer (k+2) times (source + k routers + destination) and the Data Link layer (k+1) times (once per link). Here: Network layer = 4 times, Data Link layer = 3 times.