Files
fips/docs/how-to
Johnathan Corgan 4a1d583653 fix(gateway): read conntrack over netlink when the proc file is absent
A kernel built without CONFIG_NF_CONNTRACK_PROCFS, such as Ubuntu's, has
no /proc/net/nf_conntrack. The gateway then counted zero sessions for
every mapping, so a mapping still carrying traffic was reclaimed on its
TTL and grace period alone.

When the proc file is absent, the gateway now dumps the IPv6 conntrack
table over NETLINK_NETFILTER, the request conntrack -L makes, and counts
each entry once per distinct destination, the same rule the proc parser
applies. The choice is made on every read, because the proc file appears
only once nf_conntrack is loaded. Any other proc error is still reported
without falling back. When both sources fail, the per-tick warning
carries the netlink error, and the startup line names both errors.

The dump uses netlink-packet-netfilter 0.3, the release built on the
netlink-packet-core 0.8 that rtnetlink already uses.

The gateway suite now expects the netlink source line when the
container has no proc file, and checks that the gateway counts the
session left by the HTTP request through the first virtual IP.
2026-09-19 03:54:00 +00:00
..

How-To Guides

Task-oriented, step-by-step recipes for operators with a specific goal in mind. Each guide assumes the reader already knows what FIPS is and wants to get a particular thing done — enable a feature, deploy a component, troubleshoot a class of problem.

How-to guides do not teach concepts (that is the role of design/) and do not enumerate options (that is the role of reference/). They take the reader along the shortest correct path from "I want to do X" to "X is done".

Available Guides

Guide Goal
enable-mesh-firewall.md Activate the default-deny nftables baseline on fips0
enable-nostr-discovery.md Turn on Nostr-mediated discovery (3 capabilities — resolve, advertise, open — across 5 scenarios)
deploy-tor-onion.md Run a Tor onion service for inbound FIPS connections
tune-udp-buffers.md Set host sysctls so FIPS UDP sockets don't get clamped
tune-file-descriptors.md Raise RLIMIT_NOFILE so a busy node doesn't exhaust file descriptors (EMFILE) as peer count grows
run-as-unprivileged-user.md Run the daemon under a dedicated unprivileged service account (drops the default-root posture)
deploy-gateway.md Manually deploy fips-gateway on a non-OpenWrt Linux host (LAN-to-mesh outbound + mesh-to-LAN inbound port-forwards). For the OpenWrt path, see the gateway tutorial.
troubleshoot-gateway.md Diagnostic recipes for the gateway, organised by half (outbound, inbound, common)
persistent-identity.md Provision a stable Nostr keypair so the node keeps the same npub across restarts
host-aliases.md Use shortnames (test-us01.fips, my-laptop.fips) instead of full npubs by editing /etc/fips/hosts or setting peer aliases
set-up-bluetooth-peer.md Configure a Bluetooth Low Energy peer link
set-up-80211s-mesh-backhaul.md Link OpenWrt FIPS routers over an open 802.11s radio backhaul (FIPS provides encryption, authentication, and routing)
set-up-open-access-ssid.md Broadcast the open !FIPS access SSID so phones and laptops roam onto the mesh (one ESS: save once, roam every FIPS router)
diagnose-mtu-issues.md Triage MTU-shaped failures and rule out their imposters (bufferbloat, transport saturation)
use-the-native-datagram-api.md Enable the experimental native datagram API and write a program that sends and receives datagrams by pubkey and port (no IPv6 emulation, no TUN). Read the fips group warning first
write-a-native-api-client.md Speak the native datagram API's line protocol directly from C, Python or Go, where there is no client library
serve-many-peers-on-one-thread.md Handle every native API flow from one poll loop instead of a thread per peer