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IPv6 features, header format, RFC streams

Short answer

IPv6 features include 128-bit addresses, fixed 40-byte header, extension headers, no checksum, autoconfiguration, IPsec, flow label, multicast/anycast, and neighbor discovery. Header fields: Version, Traffic Class, Flow Label, Payload Length, Next Header, Hop Limit, 128-bit source/destination. RFC streams are IETF, IAB, IRTF, and independent submission.

List the advanced features of IPv6. Describe IPv6 header format with suitable diagram. Describe internet RFC along with its streams.

Advanced features of IPv6

  1. 128-bit address space: about 3.4 x 10^38 addresses; every device can have a global address, so NAT is not needed.
  2. Simplified fixed header: 40 bytes with fewer fields, which makes routing faster.
  3. Extension headers: optional features (routing, fragmentation, authentication, ESP) are in separate headers, chained by Next Header.
  4. No header checksum and no router fragmentation: less work for routers.
  5. Auto-configuration: SLAAC and DHCPv6 let hosts configure themselves ("plug and play").
  6. Built-in security: IPsec support (AH and ESP) is part of the architecture.
  7. Better QoS: Traffic Class and 20-bit Flow Label identify packets of one flow.
  8. Multicast and anycast: broadcast is removed; multicast is more efficient.
  9. Better mobility and aggregation: Mobile IPv6 and hierarchical addressing reduce routing table size.
  10. Neighbour Discovery: ICMPv6 replaces ARP and router discovery.
  11. Jumbograms: packets larger than 64 KB are possible.

IPv6 header format

+---------+-------------+-----------------------+
| Ver (4) | Traffic     | Flow Label (20)       |
|         | Class (8)   |                       |
+---------+-------------+---------+-------------+
| Payload Length (16)   | Next    | Hop Limit   |
|                       | Hdr (8) | (8)         |
+-----------------------+---------+-------------+
| Source Address (128 bits)                     |
+-----------------------------------------------+
| Destination Address (128 bits)                |
+-----------------------------------------------+
  • Version (4 bits): value 6.
  • Traffic Class (8 bits): priority/DiffServ class.
  • Flow Label (20 bits): identifies packets of the same flow for special handling.
  • Payload Length (16 bits): size of data (and extension headers) after the base header.
  • Next Header (8 bits): type of the next header (6 = TCP, 17 = UDP, 58 = ICMPv6, 44 = fragment).
  • Hop Limit (8 bits): decremented by each router; packet is dropped at 0 (replaces TTL).
  • Source and Destination Address (128 bits each).

Total = 40 bytes.

Internet RFC and its streams

A Request for Comments (RFC) is a numbered, permanent public document that specifies Internet protocols and practices, published by the RFC Editor. Streams (RFC 4844):

  1. IETF stream: working-group documents, including all standards-track RFCs.
  2. IAB stream: architecture and policy documents.
  3. IRTF stream: research group documents.
  4. Independent submission stream: documents sent by individuals outside the other streams.

Status types include Proposed Standard, Internet Standard, Best Current Practice, Informational, Experimental and Historic.

✓ Answer checked by Claude Opus 5.5 (high effort)

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