Cisco Certified Support Technician (CCST) NetworkingNetworking FundamentalsHard
A network architect is designing an IPv6 addressing scheme for a global organization. The organization has several regional offices, each with multiple subnets. They need an addressing plan that supports a large number of subnets within each regional office and ensures unique, globally routable addresses. Which IPv6 address type is most suitable for this scenario?
- AMulticast address
- BGlobal unicast address
- CUnique local address
- DLink-local address
Show answer & explanationAnswer & explanation
Correct answer: B. Global unicast address
Global unicast addresses are globally unique and routable on the IPv6 internet, similar to public IPv4 addresses. They are essential for organizations that need to connect their various regional offices and provide internet access, while supporting a vast number of subnets.
Why the other options are wrong
- A. Multicast addresses (ff00::/8) are used to send a single packet to multiple destinations simultaneously, not for assigning unique addresses to individual hosts for global routing.
- C. Unique local addresses (ULA) (fc00::/7) are routable only within a set of cooperating sites, similar to private IPv4 addresses, and are not globally routable.
- D. Link-local addresses (fe80::/10) are only valid on a single link (network segment) and are not routable beyond that link.
IPv6 Global Unicast Address
An IPv6 Global Unicast Address (GUA) is an address that is globally unique and routable on the IPv6 internet. It is equivalent to a public IPv4 address and is primarily used for communication between different IPv6 networks across the globe.
- Globally unique and routable.
- Starts with binary 001 (currently 2000::/3 prefix).
- Used for internet communication.
- Composed of a global routing prefix, subnet ID, and interface ID.
Memory trick: L-U-G: 'Local' link, 'Unique' site, 'Global' internet.