mdnsd(8) on Solnix vs Linux and the BSDs

mdnsd is the Multicast DNS and DNS Service Discovery daemon. On Solnix it is the illumos build, run under SMF as svc:/network/dns/multicast:default. The Solnix page documents no logging signals; the NetBSD page documents SIGUSR1, SIGUSR2 and SIGINFO.

What Solnix runs

A default Solnix system runs the illumos mdnsd, published by pkgs.solnix.illumos-world-man. It is a daemon under /usr/lib, not in /usr/bin, /usr/sbin or /sbin, and no other variants are shipped. Manage it with svcadm(8) and query it with svcs(1) using svc:/network/dns/multicast:default. The page does not say where the binary lives under /usr/lib.

Differences

Compared withTopicWhat differs
NetBSDservice managementOn Solnix, mdnsd is an SMF service, svc:/network/dns/multicast:default, managed with svcadm(8) and queried with svcs(1). The NetBSD page names no service mechanism and says only that the daemon is invoked at boot time.
Source: Solnix mdnsd(8) NOTES; NetBSD mdnsd(8) DESCRIPTION
NetBSDlogging and debugging signalsThe NetBSD page has a LOGGING section: SIGUSR1 toggles extra logging, SIGUSR2 toggles packet logging, and SIGINFO dumps internal state. By default only the Error level is logged. The Solnix page documents none of this, so do not assume these signals behave the same on Solnix.
Source: NetBSD mdnsd(8) LOGGING; Solnix mdnsd(8) (no LOGGING section)
NetBSDstate dump locationNetBSD documents that SIGINFO writes a state summary to /var/log/system.log. The Solnix page names no log file or dump location.
Source: NetBSD mdnsd(8) LOGGING; Solnix mdnsd(8)
NetBSDunicast resolver roleThe NetBSD page says that on Mac OS X 10.6 mdnsd is also the system-wide Unicast DNS Resolver. The Solnix page omits this and says only that mdnsd performs unicast and multicast queries on behalf of client processes.
Source: NetBSD mdnsd(8) DESCRIPTION; Solnix mdnsd(8) DESCRIPTION
NetBSDinterface stabilityThe Solnix page marks the interface Volatile, so it may change between releases. The NetBSD page gives no stability statement.
Source: Solnix mdnsd(8) INTERFACE STABILITY; NetBSD mdnsd(8)
Linux, FreeBSD, OpenBSDno counterpart pageThe bundle has no mdnsd page for Linux, FreeBSD or OpenBSD, so the manual cannot be used to compare behaviour on those systems.
Source: Bundle header (only a NetBSD counterpart listed)
NetBSDcommand line and client toolBoth pages say mdnsd takes no user-specifiable arguments and must not be run manually. The client tool is dns-sd(8) on Solnix and dns-sd(1) on NetBSD.
Source: Solnix mdnsd(8) SYNOPSIS, SEE ALSO; NetBSD mdnsd(8) SYNOPSIS, SEE ALSO

Standards

  • POSIX: mdnsd is not a POSIX.1-2024 utility.
  • Solnix: Interface Stability: Volatile.

Writing portable scripts

  • Do not start mdnsd by hand or pass it options; both manuals say it takes no arguments. On Solnix, use svcadm enable or disable on svc:/network/dns/multicast:default, and check state with svcs.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.