Cisco CCNA (200-301)Network FundamentalsEasy
A technician boots up a new laptop and connects it to a switch port, but the DHCP server on the network is unreachable. The laptop's NIC shows an IP address of 169.254.45.12. What does this address indicate?
- AThe laptop is configured with an IPv6 link-local address
- BThe laptop self-assigned an APIPA address because it could not reach a DHCP server
- CThe laptop successfully received a static IP from the DHCP server
- DThe laptop is using a private RFC 1918 address assigned by the switch
Show answer & explanationAnswer & explanation
Correct answer: B. The laptop self-assigned an APIPA address because it could not reach a DHCP server
Addresses in the 169.254.0.0/16 range are Automatic Private IP Addressing (APIPA) addresses that a Windows host self-assigns when it cannot contact a DHCP server. This allows local link communication but no internet or cross-subnet routing.
Why the other options are wrong
- A. IPv6 link-local addresses use the fe80::/10 range, not IPv4 notation.
- C. DHCP servers do not hand out 169.254.x.x addresses; that range is reserved for self-assignment.
- D. RFC 1918 ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16, not 169.254.x.x.
APIPA
Automatic Private IP Addressing is a fallback mechanism where a Windows host assigns itself an address in 169.254.0.0/16 when DHCP is unavailable.
- Range: 169.254.1.0 – 169.254.254.255
- Indicates a failed DHCP lease request
- Allows only local subnet communication, no routing
Memory trick: '1-6-9' means 'I got nothing from DHCP, so I picked my own.'