Visual RFC.
ALL RFCs / RFC 4862
Read the RFC ↗
RFC 4862 / PROTOCOL MECHANISMS

Track preferred and valid lifetimes

04

An address can stop being preferred before it stops being valid.

Related RFCs and changes

“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.

RFC 4862 · § 5.5.4EXAMPLE
3 / 3
Track preferred and valid lifetimesAn address can stop being preferred before it stops being valid.ADDRESS LIFETIMEpreferreddeprecatedinvalidPreferred expiry ≠ valid expiryExisting traffic can continue appropriately on a deprecated address
03
Valid lifetime expires: remove it from usable addresses.

Valid lifetime expires: remove it from usable addresses.

Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
KEY POINT

Preferred lifetime expiry deprecates the address; valid lifetime expiry invalidates it.

  • Preferred lifetime expiry deprecates the address; valid lifetime expiry invalidates it.
  • A deprecated address may continue existing communication; choose a preferred alternative for new communication when available.
DETAILS

The drawing is a simplified worked example. Follow the linked RFC and its updates for implementation requirements.

Read the RFC section ↗

Diagrams simplify the RFC. Read the linked sections for complete requirements.

Privacy
All chapters in this RFC
  1. Form a tentative link-local address
  2. Check a tentative address for duplicates
  3. Combine an advertised prefix and identifier
  4. Track preferred and valid lifetimes
  5. Renumber without an instant cutover

Drawing view

Scroll the drawing to see every part. Playback controls stay above it.

RFC 9700 / CHAPTERS

Chapters

For full details, tables, algorithms, and exceptions, read the original RFC.

RFC status and corrections ↗