What it means
A device can have several addresses at once. Local addresses are used within a network; an internet-facing address may be shared through NAT. Dynamic configuration can change addresses over time. An address alone does not identify a person or prove that a service is reachable.
How this affects everyday use
Duplicate manual addresses, a wrong subnet or missing configuration can interrupt connectivity. A changed address can also break a saved printer or server connection even though the device is healthy.
A practical example
A printer receives a new address after a lease change, while a computer still sends jobs to the old one.
What to check
- Inspect the relevant interface's current address and subnet.
- Compare the target address with the router's lease table.
- Check for conflicts and distinguish IPv4 from IPv6 results.
Practical next steps
- Use the intended automatic configuration for ordinary clients.
- Create a documented DHCP reservation for a stable local endpoint.
- Update stale connections after confirming the correct device.
Keeping it reliable
Keep address plans and reservations recorded. Avoid assigning random addresses or treating a public address as proof of identity. IPv6 exposure and firewall rules need their own review.