Distinguishing IPv6 from IPv4: Address Length
IPv4 and IPv6 differ fundamentally in address size: IPv4 addresses are 32 bits, while IPv6 addresses are 128 bits. Therefore, the correct option is (iii) IPv6 uses 128-bit addresses, while IPv4 uses 32-bit addresses.
Key terms:
- IPv4
- IPv6
- IP address
- Address length
Note: This section focuses on the specific multiple-choice distinction about address bit-length.
Fast elimination strategy
If the options mention 128-bit for IPv6 and 32-bit for IPv4, then you’re looking at the correct pairing for the address-length difference.
Why option (iii) is correct
An IP address length determines how many unique addresses can be represented:
- IPv4 uses 32-bit addresses, meaning the address space is size .
- IPv6 uses 128-bit addresses, meaning the address space is size .
This is why IPv6 was designed with a much larger address space (conceptually), but for your question, the deciding fact is simply the bit-length mapping: IPv6 = 128-bit, IPv4 = 32-bit.
Key terms (reinforced):
- IPv4
- IPv6
- Address space
Answering the multiple-choice question
- 1Step 1
Recall that IPv4 addresses are 32-bit, while IPv6 addresses are 128-bit.
- 2Step 2
Choose the option that states: “IPv6 uses 128-bit addresses, while IPv4 uses 32-bit addresses.”
- 3Step 3
Eliminate options where IPv4 is incorrectly assigned 128-bit addresses or IPv6 is incorrectly assigned 32-bit addresses.
Common confusions
High-level progression of addressing needs
32-bit addressing
IPv4 eraIPv4 uses 32-bit addresses, defining its address space as "
128-bit addressing
IPv6 introductionIPv6 uses 128-bit addresses, defining its address space as "
Knowledge Check
Which statement correctly distinguishes IPv6 from IPv4?