rdnssd - IPv6 Recursive DNS Server discovery Daemon
] [-H merge-hook
] [-r resolv-file
] [-u username
is a daemon program providing client-side support for DNS
configuration using the Recursive DNS Server (RDNSS) option, as described in
RFC 5006. Its purpose is to supply IPv6 DNS resolvers through stateless
autoconfiguration, carried by Router Advertisements.
rdnssd parses RDNSS options and keeps track of resolvers to write nameservers
entries to a resolv.conf(5) configuration file. By default, it writes its own
separate file, and may call an external hook to merge it with the main
/etc/resolv.conf. This is aimed at easing coexistence with concurrent daemons,
especially IPv4 ones, updating /etc/resolv.conf too.
On Linux, since version 2.6.24, rdnssd takes advantage of a new netlink
interface, forwarding RDNSS options validated by the kernel to userland.
Otherwise, it merely listens to all ICMPv6 traffic through a raw socket.
- -f or --foreground
- Do not detach from the console. Run the program in the
- -H merge-hook or --merge-hook merge-hook
- Execute this hook whenever resolv.conf is updated. If this
option is not specified, then no hook will be called.
- -h or --help
- Display some help and exit.
- -p pidfile or --pidfile pidfile
- Override the location of the pidfile.
- -r resolv-file or --resolv-file
- Set the path to the generated resolv.conf file.
- -u username or --user username
- Override the user that the program will run as. By default,
it runs as nobody.
- -V or --version
- Display program version and license and exit.
- A basic merge hook shipped with rdnssd, to be called with
the -H option.
- The default resolv.conf(5) file that rdnssd writes its
- The process-id file.
rdnssd does not keep track of the lifetimes of the routers associated with some
DNS resolvers, whereas it should to strictly comply with RFC 5006.
When rdnssd uses a raw socket instead of the netlink kernel interface, it does
not validate received Neighbor Discovery traffic in any way. For example, it
will always consider Router Advertisement packets, whereas it should not if
the host is configured as a router. When the netlink interface is used, such
validation is done by the kernel.
resolv.conf(5), rdisc6(8), ipv6(7)
Pierre Ynard <linkfanel at yahoo.fr>