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Difficulty: MediumIPv6 Addressing Concepts and Header Structure

A network engineer is configuring a static route on a core router using the uncompressed IPv6 next-hop address 2001:0db8:0000:0000:0008:0000:0000:0001. According to RFC 5952 IPv6 addressing standards, which of the following represents the correct compressed form of this address?

  1. 2001:db8::8:0:0:1Answer
  2. B
    2001:db8::8::1
  3. C
    2001:db8:0:0:8::1
  4. D
    2001:db8:0:0:8:0:0:1

Answer

The address 2001:db8::8:0:0:1 is the correct compressed form.
The correct representation, 2001:db8::8:0:0:1, suppresses leading zeros in each hexadecimal word and compresses the first sequence of contiguous zero blocks using ::. Per RFC 5952, when two zero sequences have the same length, the first sequence must be compressed.

Step-by-Step Solution

1
Suppress leading zeros in each 16-bit hexadecimal field.
2001:0db8 becomes 2001:db8, 0008 becomes 8, and 0001 becomes 1.
Leading zeros within any 4-digit hexadecimal group are optional and omitted for brevity.
2
Identify contiguous blocks of all-zero fields.
There are two separate sequences of two consecutive zero blocks: blocks 3-4 and blocks 6-7.
IPv6 allows replacing contiguous zero blocks with a double-colon (::).
3
Apply the double-colon (::) according to RFC 5952 rules.
The first sequence of two zero blocks is replaced by ::, yielding 2001:db8::8:0:0:1.
The double-colon can only be used once per address. When zero sequences are of equal length, standard conventions require compressing the first occurrence.

Key Concept

IPv6 Address Compression Rules (RFC 5952)
Estimated Time:1m 0s
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Topics

IPv6 Addressing Concepts and Header Structure

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