Files
fips/docs/tutorials
Johnathan Corgan 28f9fc007a Move the gateway's default DNS port from 5353 to 5365
5353 is the mDNS port, which the daemon's LAN rendezvous, Avahi and
systemd-resolved can hold. On an OpenWrt access point with the gateway
enabled, the gateway lost the port to the daemon's mDNS responder and
dnsmasq sent .fips queries to a responder that does not answer them.
5365 is unassigned by IANA and not used by any common resolver.

The OpenWrt init script now points dnsmasq at the port
gateway.dns.listen actually sets, falling back to the new default, and
when it swaps the .fips forwarding it clears every loopback .fips entry
rather than four fixed ones, so a stale entry for an old or custom port
does not linger. Forwards to other hosts and other domains are kept.
The shipped OpenWrt config and the example config leave the listen
line at the default.

fips.yaml is a conffile on OpenWrt, and fips-ap-setup edits it, so
routers that set up an access point would keep the old explicit
listen: "[::1]:5353" across an upgrade and stay broken after the
default moved. The first-boot setup script, which every install and
upgrade path runs before the services start, now rewrites that exact
shipped line to the line a fresh install ships and logs that it did;
any other value is left as configured. The script is sourced rather
than executed on the SDK-feed and sysupgrade paths, so the migration
runs last, cannot end the script early and cannot change its exit
status. The script also removes stale loopback .fips forwarding entries
for port 5353.

The gateway warns at startup when it is configured on 5353, whether or
not the bind succeeds, since an mDNS responder can take the port later.

The OpenWrt scenario harness checks the port the init script reads,
that its default matches the gateway's, and the swap's cleanup against
a uci stub. It also runs the real setup script executed by both
package managers' upgrade scripts and sourced in a subshell, and checks
the negative, missing-file, repeat-run and stale-entry cases. The
dns-resolver and deb-install harnesses check that the gateway binds the
new default.
2026-09-27 19:35:48 +00:00
..

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 ssh from DNS query through session setup to the far-side TUN, using fipstop and fipsctl to 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-gateway on an OpenWrt access point so unmodified LAN hosts can reach <npub>.fips destinations 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.