220-1101 Question 146
Single answerIPv6A technician is configuring a small office printer on a network that uses IPv6. A user reports the printer can be reached from computers on the same LAN, but devices in another subnet cannot connect to it by IPv6 address. The printer currently has only an address that begins with fe80::. Which of the following should the technician do to allow the printer to communicate across routers on the IPv6 network?
- A
Assign or obtain a global unicast IPv6 address for the printer
- B
Change the printer to use only an APIPA address in the 169.254.x.x range
- C
Configure the printer with another link-local IPv6 address in the fe80::/10 range
- D
Replace the IPv6 address with a loopback address of ::1
Show answer and explanation
Correct answer: A
Explanation
In IPv6, link-local addresses in the fe80::/10 range are automatically used for communication on the local link, such as neighbor discovery and local subnet access. However, routers do not forward link-local traffic between subnets. For cross-subnet communication, a host needs a routable address, typically a global unicast address from the 2000::/3 range. In practice, technicians should verify whether the device is receiving a global address through Stateless Address Autoconfiguration (SLAAC), DHCPv6, or manual configuration. This aligns with standard IPv6 addressing behavior defined by IETF guidance, including RFC 4291 for IPv6 addressing architecture and RFC 4862 for SLAAC.
- A. Correct.
Correct. An address beginning with fe80:: is a link-local IPv6 address, which is valid only on the local network segment and is not routed between subnets. To communicate with devices on other IPv6 networks, the printer needs a routable IPv6 address, typically a global unicast address, which may be assigned manually, by SLAAC, or through DHCPv6 depending on the network design.
- B. Incorrect.
Incorrect. 169.254.x.x is an IPv4 APIPA range, not an IPv6 addressing solution. APIPA is used for local IPv4 communication when no DHCP server is available, and it would not solve an IPv6 routing issue.
- C. Incorrect.
Incorrect. Another fe80::/10 address would still be link-local and would remain non-routable beyond the local segment. This distractor targets the misconception that changing the link-local address itself can make remote communication work.
- D. Incorrect.
Incorrect. ::1 is the IPv6 loopback address and refers only to the local device itself. It is used for internal testing on the same host and cannot be used by other devices to reach the printer over the network.