# IPv6 expansion and header facts

Subject: Computer Networks

Exam: TEE

Reader: https://deep-learning-study-room.vercel.app/cn/#tee/formulas/tee-formulas/exam-headers

Canonical: https://deep-learning-study-room.vercel.app/read/cn/tee/formulas/tee-formulas--exam-headers/

TEE · Complete six-unit quick reference · current syllabus 702AI0C023



$$
\mathrm{omitted\ groups}=8-\mathrm{visible\ groups}
$$



Count every written hexadecimal group, including a written 0. Expand :: once and pad every group to four hexadecimal digits. Final Q4(a) asks expansion and header comparison; re-exam Q4(a) asks the IPv6 packet format.

For diagrams: IPv6 has a fixed 40-byte base header; its payload-length field excludes that base header. IPv4 uses IHL in 32-bit words. Extra packet-length calculations are in optional practice.

[Worked IPv6 expansion](https://deep-learning-study-room.vercel.app/read/cn/tee/read/ipv6--expand-1/)