What Does Global Unicast Address Mean in 200-301?
Also known as: GUA, public IPv6 address
Quick Definition
A globally routable IPv6 address equivalent to a public IPv4 address (2000::/3).
Full Definition
Global Unicast Addresses (GUAs) are the IPv6 equivalent of public IPv4 addresses — globally routable on the Internet. They begin with the range 2000::/3 (first hex digit 2 or 3). ISPs assign GUA prefixes to organisations, which then subnet them for internal use. Devices receive GUAs through SLAAC, DHCPv6, or manual configuration.
Real-World Example
2001:db8::/32 is a documentation prefix (like 192.0.2.0/24 in IPv4) used in examples. A real GUA might look like 2403:300:a42:1::1/64.
Exam Trap — Don't Get Fooled
GUAs are globally routable; link-local addresses (FE80::/10) are not. A device can have multiple GUAs on one interface — this is normal in IPv6.
Related 200-301 Terms
An IPv6 address automatically assigned to every interface, only valid on the local link (FE80::/10).
An IPv6 mechanism where hosts automatically generate their own global address from the network prefix advertised by a router.
A method of generating a 64-bit IPv6 interface ID from a 48-bit MAC address.
Frequently Asked Questions
What does Global Unicast Address mean on the 200-301 exam?
Global Unicast Addresses (GUAs) are the IPv6 equivalent of public IPv4 addresses — globally routable on the Internet. They begin with the range 2000::/3 (first hex digit 2 or 3). ISPs assign GUA prefixes to organisations, which then subnet them for internal use. Devices receive GUAs through SLAAC, DHCPv6, or manual configuration.
How does Global Unicast Address appear as a trap on the 200-301?
GUAs are globally routable; link-local addresses (FE80::/10) are not. A device can have multiple GUAs on one interface — this is normal in IPv6.
Can you give a real-world example of Global Unicast Address?
2001:db8::/32 is a documentation prefix (like 192.0.2.0/24 in IPv4) used in examples. A real GUA might look like 2403:300:a42:1::1/64.
How important is Global Unicast Address on the 200-301 exam?
Global Unicast Address falls under the IPv6 domain of the 200-301 exam. Understanding it in context with related terms like link-local-address and slaac is essential for answering scenario-based questions correctly.