IPv6 Subnetting Worksheet Audit

About this interactive

IPv6 subnetting from a /48 is counting. The bits between the prefix you are given and /64 are your subnet ID: a /48 leaves 16 of them, a /56 leaves 8, and n bits number 2^n subnets. Each hex digit is a nibble of 4 bits, so a prefix that ends on a nibble fixes a whole number of hex digits. The first subnet is all zeros, so the nth subnet's ID is n - 1 written in hex: the 50th is 49, 0011 0001 in binary, 31 in hex, and its network is the /48 with :31 in the fourth hextet. Read an ID back by converting it to decimal and adding one. A host's network is its first four hextets with the interface ID set to zero, written shortest: leading zeros dropped, and :: once, for the longest run of zero hextets. This audit gives you a worksheet to check line by line. Some answers are wrong; find each one. Lines that look odd may still be right, so work every value out. After you submit, every wrong line is shown with what is wrong and the fix.

What you'll learn

Check IPv6 subnetting work from a /48: the subnet-ID bits and /64 count a prefix length gives, the subnet ID of the nth subnet, and the subnet number behind an ID
Find and fix the slips: a count that does not match the prefix, a subnet number not reduced by one, a binary slip, an ID left in decimal, and a host's /64 prefix with its subnet ID dropped or shortened wrongly

Aligned to

Cisco CCNA

1.8 Configure and verify IPv6 addressing and prefix

Cisco CCST Networking

2.3 Identify IPv6 addresses and prefix formats

CompTIA Network+

3.4 Given a scenario, implement IPv4 and IPv6 network services

Key terms

IPv6 Prefix Length: A value expressed in slash notation that identifies how many leading bits of an IPv6 address represent the network portion, functioning similarly to CIDR notation in IPv4.
Hexadecimal: A base-16 number system using digits 0–9 and letters A–F; each hex digit maps to exactly 4 bits, making it a compact shorthand for representing binary data.
Nibble: A group of exactly 4 bits, equivalent to one hexadecimal digit; two nibbles make up one byte.
Hextet: A group of four hexadecimal digits in an IPv6 address; eight hextets separated by colons form a complete 128-bit IPv6 address.
Interface ID: The last 64 bits of an IPv6 address that uniquely identify a specific interface or node within a network, equivalent to the host portion in IPv4.

Topics

Ipv6 Ipv6 Subnetting Prefix Length Subnet Id Hexadecimal Interactive Spot The Error

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