200-301 Question 102
Select 3A network administrator is configuring IPv6 addresses on devices in a network. One device is assigned the address 'fe80::1', while another is assigned '2001:db8:abcd::1'. A third device is assigned 'fd00::1'. Which of the following statements about these IPv6 addresses is correct?
- A
'fe80::1' is a link-local unicast address.
- B
'2001:db8:abcd::1' is a unique local unicast address.
- C
'fd00::1' is a global unicast address.
- D
'2001:db8:abcd::1' is a global unicast address.
- E
'fd00::1' is a unique local unicast address.
Show answer and explanation
Correct answers: A, D, E
Explanation
IPv6 unicast addresses are categorized into global unicast, unique local unicast, and link-local unicast. Global unicast addresses (e.g., '2001:db8:abcd::1') are routable on the public internet, unique local addresses (e.g., 'fd00::1') are used within private networks, and link-local addresses (e.g., 'fe80::1') are valid only within a single link. Understanding these categories helps in accurately configuring and troubleshooting IPv6 networks.
- A. Correct.
'fe80::1' is indeed a link-local unicast address. Link-local addresses always begin with 'fe80::' and are valid only within the same link or segment.
- B. Incorrect.
'2001:db8:abcd::1' is not a unique local unicast address; it is part of the global unicast address space. Global unicast addresses typically start with '2000::/3'.
- C. Incorrect.
'fd00::1' is not a global unicast address. Unique local unicast addresses (ULA) start with 'fd00::/8', while global unicast addresses typically start with '2000::/3'.
- D. Correct.
'2001:db8:abcd::1' is a global unicast address. Global unicast addresses are routable on the public internet and typically begin with '2000::/3'.
- E. Correct.
'fd00::1' is a unique local unicast address. Addresses in the range 'fd00::/8' are reserved for unique local addressing, which is used for internal networks and not routable on the public internet.