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Difficulty: MediumIPv6 Addressing and Deployment

A network administrator is deploying IPv6 on an enterprise subnet. The design requires host devices to automatically generate their own global unicast IP addresses using prefix information advertised by the local router, while simultaneously obtaining DNS server IP addresses from a central DHCPv6 server. Which of the following configurations and address assignments correctly support this deployment strategy? (Select TWO.)

  1. The local router must transmit Router Advertisement (RA) frames with the Managed Address Configuration (M) flag set to 0 and the Other Configuration (O) flag set to 1.Answer
  2. B
    The enterprise DNS server must be configured with IPv4 A records to resolve hostnames to the newly assigned IPv6 global unicast addresses.
  3. Host devices dynamically formulate their 128-bit global unicast address by combining the advertised /64 network prefix with an interface identifier derived via SLAAC.Answer
  4. D
    The default gateway on host interfaces must be manually configured using the compressed address 2001:db8::1::10/64.

Answer

The correct configurations are setting the Router Advertisement flags to M=0 and O=1 (stateless DHCPv6 mode) and allowing host devices to combine the advertised /64 network prefix with a SLAAC-generated interface identifier.
Stateless DHCPv6 mode allows clients to derive their global unicast IPv6 address using SLAAC (combining the router's /64 prefix advertisement with a 64-bit host interface ID) while querying a DHCPv6 server for DNS details triggered by the RA flag configuration M=0 and O=1.

Step-by-Step Solution

1
Analyze the autoconfiguration requirement for host address generation.
Hosts generating their own global unicast addresses from advertised prefixes require SLAAC, which uses RA prefix information combined with a 64-bit interface identifier.
SLAAC eliminates the need for a stateful DHCPv6 server to assign IP addresses.
2
Determine the required Router Advertisement (RA) flag settings for Stateless DHCPv6.
The Managed Address Configuration flag must be M=0 (no stateful IP assignment) and the Other Configuration flag must be O=1 (obtain additional settings like DNS via DHCPv6).
This combination signals to clients that IP addressing comes from SLAAC while DNS server information comes from a stateless DHCPv6 server.
3
Evaluate record types and address compression syntax.
DNS requires AAAA records for IPv6 mapping, and valid IPv6 address notation permits only one double-colon (::) per address.
A records only support 32-bit IPv4 addresses, and multiple double-colons create unresolvable ambiguity in 128-bit address expansion.

Key Concept

Stateless Address Autoconfiguration (SLAAC) with Stateless DHCPv6
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Topics

IPv6 Addressing and Deployment

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