Mesh/Firmware/Zeroconf

From Sudo Room
Revision as of 00:17, 6 May 2014 by Jwentwistle (talk | contribs) (added nss-mdns details)
Jump to navigation Jump to search

We need a basic DNS client (and server) on the nodes. Zero-configuration (zeroconf) networking is software which configures a domain name server (DNS), dynamic host configuration protocol (DHCP), and other network settings with no configuration. We want to use the Service Location Protocol (SLP) to implement a domain service. The domain server returns a service (or files) from a destination (typically based on an IP address). Such that peoplesopen.net resolves 199.175.52.221 as the IP address.

Software

avahi

An implementation of the DNS Service Discovery and Multicast DNS specifications for zero configuration networking. It uses D-Bus for communication between user applications and a system daemon. The daemon is used to coordinate application efforts in caching replies, necessary to minimize the traffic imposed on networks.

Avahi allows you to access computers using their hostnames. (documentation from archwiki) The services on the network can be hosted and discovered through the command line. Note: you must install nss-mdns for this to work, and have avahi-daemon.service enabled and running.

The program consists of these programs:

Features:

  • Embeddable mDNS stack (i.e. mDNS stack available as library)
  • Ability to reflect mDNS traffic between multiple subnets
  • Ability to configure a unicast DNS server automatically from server data published on the LAN
  • Wide area DNS-SD support (read-only for now)
  • Interface to GLIBC NSS using nss-mdns

nss-mdns

The software providing host name resolution via Multicast DNS, effectively allowing name resolution by common Unix/Linux programs in the ad-hoc mDNS domain (*.local).

mdns-utils

The OpenWRT package mdns-utils is actually just compiling part of Apple's mDNSResponder.

The mDNSClient utility only outputs lines to stderr (name, service type, and domain):

 *** Found name = 'Foo', type = '_afpovertcp._tcp.', domain = 'local.'

The code that outputs this line is in the file mDNSResponder/mDNSPosix/Client.c in the function BrowseCallback.

Documentation

New DNS technologies on the LAN: mDNS, DNS-SD, LLMNR, PNRP

mesh DNS software: HypeDNS vs decentralized servers