Files
fips/docs/design
Johnathan Corgan 6f8590cd92 docs: flag the bloom-filter design doc as describing the retired v1.5
The code on next is currently v1 after the v1.5 removal during the
sans-IO refactor, but this doc still described the abandoned v1.5 design
as implemented, which is misleading. Add an interim status banner
pointing at v2 as the pending target until the doc is rewritten to v2.
2026-07-12 15:36:54 +00:00
..

FIPS Design

Architectural and protocol-level explanations for FIPS — the why and the how behind the wire and the system. For wire formats and configuration keys, see reference/. For task recipes, see how-to/. For end-to-end lessons, see tutorials/.

Reading Order

Start with fips-concepts.md for the novice-friendly framing of what FIPS is and why, then move to fips-architecture.md for the protocol stack, identity model, and two-layer encryption walkthrough. From there, follow the protocol stack from bottom to top. After the stack, fips-mesh-operation.md explains how the pieces work together at runtime. Cross-cutting and supporting documents cover specific subsystems in detail.

Foundations

Document Description
fips-concepts.md What FIPS is, why it exists, mental model
fips-architecture.md Protocol stack, identity, two-layer encryption
fips-prior-work.md Designs and protocols FIPS builds on

Protocol Stack

Document Description
fips-transport-layer.md Transport layer: datagram delivery over arbitrary media
fips-mesh-layer.md FIPS Mesh Protocol (FMP): peer authentication, link encryption, forwarding
fips-session-layer.md FIPS Session Protocol (FSP): end-to-end encryption, sessions
fips-ipv6-adapter.md IPv6 adaptation: TUN interface, DNS, MTU enforcement

Cross-Cutting

Document Description
fips-mmp.md Metrics Measurement Protocol (link + session)
fips-mtu.md Path MTU model, encapsulation overhead, PMTUD
fips-security.md fips0 interface threat model and default-deny baseline

Mesh Behavior

Document Description
fips-mesh-operation.md How the mesh operates: routing, discovery, error recovery
fips-nostr-discovery.md Optional Nostr-mediated peer discovery and UDP NAT hole-punch
port-advertisement-and-nat-traversal.md Nostr-signaled port advertisement and UDP NAT-traversal protocol; generic, with FIPS as an example implementation

Deeper Dives

Document Description
fips-spanning-tree.md Spanning tree algorithms: root discovery, parent selection, coordinates
fips-bloom-filters.md Bloom filter properties: FPR analysis, size classes, split-horizon
spanning-tree-dynamics.md Spanning tree walkthroughs: convergence scenarios, worked examples

Adjacent Components

Document Description
fips-gateway.md fips-gateway service: outbound (LAN-to-mesh) DNS-proxy + virtual-IP NAT and inbound (mesh-to-LAN) port-forwarding, sharing one nftables table