Examkin

Question

Difficulty: HardIPv6 Addressing and Deployment

A network engineer is deploying IPv6 across an enterprise environment and configuring dynamic address assignment and routing mechanisms. Match each IPv6 deployment component or address feature on the left to its corresponding technical operation or scope on the right.

  • Stateless DHCPv6 (M=0, O=1)Hosts obtain network prefixes and auto-generate IP addresses via Router Advertisements, while querying a server exclusively for non-address parameters like DNS.
  • EUI-64 Interface IdentifierGenerates a 64-bit host portion by inserting 0xFFFE into a 48-bit MAC address and flipping the 7th bit (Universal/Local bit).
  • Unique Local Address (fc00::/7)Provides globally unique non-routable IPv6 addressing designated strictly for internal site communication.
  • All-DHCPv6-Relay-Agents/Servers Multicast (ff02::1:2)Serves as the link-local destination address for client Solicit messages forwarded across network segments by relay agents.

Answer

Stateless DHCPv6 (M=0, O=1) matches hosts auto-generating IP addresses via SLAAC while querying DHCPv6 for non-address settings. EUI-64 Interface Identifier matches inserting 0xFFFE into a MAC address and flipping the 7th bit. Unique Local Address (fc00::/7) matches globally unique non-routable addressing for internal sites. All-DHCPv6-Relay-Agents/Servers Multicast (ff02::1:2) matches the link-local destination address used for relaying client Solicit messages.
Stateless DHCPv6 (M=0, O=1) allows hosts to use SLAAC for IP generation while fetching extra options like DNS via DHCPv6. Modified EUI-64 expands a 48-bit MAC address into a 64-bit interface ID by inserting 0xFFFE and inverting the 7th bit. Unique Local Addresses (fc00::/7) provide internal private IP routing within enterprise boundaries without internet accessibility. The multicast address ff02::1:2 specifically targets local DHCPv6 relay agents and servers.

Step-by-Step Solution

1
Analyze Router Advertisement flags for dynamic IPv6 address deployment modes.
M=0 indicates that stateful address assignment is disabled, and O=1 indicates that other configuration parameters (such as DNS) are available via DHCPv6. This corresponds to Stateless DHCPv6 combined with SLAAC.
Understanding ICMPv6 RA flag combinations is essential for deploying stateless versus stateful IPv6 autoconfiguration.
2
Evaluate host interface identifier generation mechanisms using EUI-64.
Modified EUI-64 splits the MAC address into two 24-bit halves, inserts 16 bits (0xFFFE), and flips the Universal/Local (U/L) bit (the 7th bit of the first octet).
Verifying correct EUI-64 translation rules ensures proper identification of automatically derived IPv6 host addresses.
3
Classify IPv6 address scopes and prefixes for enterprise design.
The fc00::/7 prefix defines Unique Local Addresses (ULA), which are internal, non-globally-routable IPv6 addresses.
Distinguishing between Global Unicast, Link-Local, and Unique Local prefixes is critical for secure network architecture.
4
Identify specialized IPv6 multicast addresses used during address assignment.
ff02::1:2 represents the All-DHCPv6-Relay-Agents/Servers link-local multicast group.
DHCPv6 clients communicate with local servers or relay agents using designated multicast groups rather than broadcast mechanisms.

Key Concept

IPv6 Address Scopes, EUI-64 Derivation, and Autoconfiguration Mechanisms (SLAAC / DHCPv6)
Rate this question

Topics

IPv6 Addressing and Deployment

More questions from this topic