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Johnathan Corgan
bf4e0df8c5
A busy node opens roughly three file descriptors per established UDP peer (a connect()-ed socket plus a 2-FD drain self-pipe), so the default 1024 soft RLIMIT_NOFILE is exhausted near 320 peers and further peer admission, handshakes, and discovery fail with EMFILE. Document the FD budget, the symptom, and the systemd (LimitNOFILE drop-in) and OpenWrt (procd nofile) procedures to raise it, plus how to verify the per-peer ratio is bounded. Link the new guide from the how-to index.
2.2 KiB
2.2 KiB
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 |
| diagnose-mtu-issues.md | Triage MTU-shaped failures and rule out their imposters (bufferbloat, transport saturation) |