Once the network is addressed, you have to verify it. Two universal tools do the job: ping tests whether a destination is reachable, and traceroute reveals the path taken hop by hop.

What they tell you

• ping — does the destination answer? (round-trip time).
• traceroute / tracert — which routers do we go through?
• Both work over IPv4 and IPv6.

On a Windows PC in Packet Tracer you use the command prompt; on a Cisco device the same commands exist in privileged mode.

C:> ping 2001:db8:acad:1::1
C:> tracert 192.168.1.1
R1# ping 192.168.1.10
R1# traceroute 2001:db8:acad:2::10

A successful ping confirms end-to-end connectivity; a lost ping followed by a traceroute that stops at a specific hop pinpoints where the path breaks. These tools are your first diagnostic reflex, in IPv4 as much as in IPv6.

Key point: ping tests reachability, traceroute reveals the path; both work over IPv4 and IPv6. See Lab 14 – Testing connectivity with ping and traceroute.