Updated: October 28, 2024 |
Multicast and Unicast DNS daemon
mdnsd
QNX Neutrino
The mdnsd daemon (also known as mDNSResponder on some systems) is a daemon that provides Multicast DNS and DNS Service Discovery.
The mdnsd daemon listens on UDP port 5353 for Multicast DNS Query packets. When it receives a query for which it knows an answer, mdnsd issues the appropriate Multicast DNS Reply packet.
It also performs Unicast and Multicast DNS Queries on behalf of client processes, and maintains a cache of the replies.
Logging
There are several methods that you can use to examine mdnsd's internal state for debugging and diagnostic purposes. The syslogd logging levels map as follows:
By default, only log level Error is logged.
A SIGUSR1 logs the current state information.
slay -s SIGUSR1 mdnsd
A SIGUSR2 signal toggles additional logging and packet logging:
slay -s SIGUSR2 mdnsd
For more information on:
For the source code to mdnsd, see http://developer.apple.com/darwin/projects/bonjour/.