Johnathan Corgan
0c52763f5f
The packaged mesh firewall had one chain, on the input hook. A fips-gateway port forward is a DNAT in prerouting, so its traffic is routed through the forward hook and never met that chain or its fips.d drop-ins. With the firewall loaded, every mesh node that could reach the gateway reached every forward, and the only way to restrict one was a separate table loaded by hand, which no test exercised. fips.nft now has a second chain in the inet fips table, on the forward hook. It returns for traffic not arriving on the mesh interface, accepts established and related packets, includes drop-ins from /etc/fips/fips.d/forward/*.nft, and then accepts the remaining port-forwarded connections with a counter. Forwards stay open to the mesh by default, so nothing changes on upgrade; a forward is restricted by a drop-in that accepts the allowed mesh addresses for its target address and port and drops the rest. A missing forward/ directory is fine. The static gateway suite gains a phase that loads the tree's fips.nft on the gateway with the drop-in taken from the deployment how-to, and checks that the allowed node reaches the TCP and UDP forwards, the other node is refused on both with each refusal counted by its own drop rule, and a forward with no drop-in line stays open. A packaging test checks the chain's rules and their order on every target. The how-to, the firewall guides, the troubleshooting step, the design and reference documents and the hosting tutorial describe the new chain and drop-in directory in place of the hand-loaded table, and say what happens to a hand-loaded table or a kept, edited fips.nft.
Tutorials
If you have just installed FIPS, this is where to start. The tutorials below take you from a freshly-installed daemon to a node that:
- Has joined the public test mesh and can reach other nodes on it.
- Carries a stable identity that other operators can address.
- Discovers peers — and is discoverable — over Nostr.
- Hosts and consumes real services across the mesh.
Each tutorial is a complete, working session at the keyboard. You configure something, restart the daemon, watch it come up, and verify the result. The point is to build muscle memory, not to cover every option.
Read them in order. Each tutorial assumes the state the previous one left you in. If you skip ahead, the cross-references that lead you back may not match what you have on disk.
The new-user progression
| # | Tutorial | What you'll do |
|---|---|---|
| 1 | join-the-test-mesh.md | Add one public test peer to your config, watch the link come up, ping that peer and a second mesh node it routes you to. The starting point for everything else. |
| 2 | persistent-identity.md | Pin your daemon to a stable Nostr keypair so your address stops changing on every restart. Other operators can now add you to their peers: lists; the services you host get a fixed name. |
| 3 | resolve-peers-via-nostr.md | Stop hard-coding peer addresses. Drop the address line from your peer entry and let the daemon look up the current endpoint from public Nostr relays at dial time. |
| 4 | advertise-your-node.md | Publish your own UDP endpoint to Nostr so any operator who knows your npub can reach you, with a short final section on udp:nat best-effort hole-punching for nodes without a directly reachable UDP endpoint. |
| 5 | open-discovery.md | Switch to policy: open and let your peer list populate itself from the ambient fips-overlay-v1 namespace. Hands-off mesh participation. |
| 6 | reach-mesh-services.md | Drive ordinary IPv6 tools — ping6, nc, traceroute6, curl, ssh — at mesh nodes by <npub>.fips. Get a feel for the daemon's IPv6 adapter, which makes unmodified IPv6 software work over the mesh. |
| 7 | host-a-service.md | Bring up an HTTP server bound to fips0 so mesh nodes can reach it, with a deliberate exposure decision (mesh-only vs every interface), and the mesh firewall as a default-deny baseline. The peer ACL (a separate, transport-layer control over which npubs may peer with your node) is briefly mentioned alongside. |
| 8 | ground-up-mesh.md | Bring up a second deployment mode: two devices joined by Ethernet (or WiFi, or BLE) with no IP infrastructure between them. The mesh emerges from layer 2 up. Coexists with overlay peers — the same daemon can carry both. |
After tutorial 8 you have a fully participating mesh node that reaches services hosted by other mesh nodes and hosts services of its own, with identity, discovery, reachability, an explicit exposure policy, and an understanding of both deployment modes — overlay on top of existing IP, and ground-up where the mesh is the network.
There are also two side trips you can take:
-
ipv6-adapter-walkthrough.md — trace one
sshfrom DNS query through session setup to the far-side TUN, usingfipstopandfipsctlto watch each step. Optional, but if you like seeing how the pieces fit together, this is the doc that shows you. Take it any time after tutorial 1. -
native-api-walkthrough.md — write a program against the experimental native datagram API, addressing a peer by public key and port with no IPv6 emulation and no TUN. Runs two throwaway nodes on one machine, so it needs no mesh and no root, and you can take it without doing the tutorials first.
Advanced
These are not part of the new-user progression. They assume you have already worked through the tutorials above and now want to fold FIPS into a wider network deployment.
- deploy-fips-gateway.md — Stand up a
fips-gatewayon an OpenWrt access point so unmodified LAN hosts can reach<npub>.fipsdestinations through a DNS- allocated virtual IPv6 pool and kernel nftables NAT, with no per-host FIPS install. Also walks through one inbound port forward exposing a LAN service to mesh peers. Aimed at operators bridging a LAN segment into the overlay from the edge router. For a non-OpenWrt host the same deployment is in ../how-to/deploy-gateway.md.
When to use the how-to guides instead
The tutorials here walk through one specific path each. The how-to guides under ../how-to/ are the operator recipes — alternative provisioning paths, less-common configurations, troubleshooting techniques. Once you have the shape of FIPS in your head from these tutorials, the how-tos are where you'll go to look up "how do I do X?" without being walked through the surrounding context.