summaryrefslogtreecommitdiff
path: root/man
diff options
context:
space:
mode:
Diffstat (limited to 'man')
-rw-r--r--man/systemd.network.xml39
1 files changed, 23 insertions, 16 deletions
diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 08dd157e31..0af927db19 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -467,24 +467,31 @@
<varlistentry>
<term><varname>Domains=</varname></term>
<listitem>
- <para>The domains used for DNS host name resolution on this link. Takes a list of DNS domain names which
- are used as search suffixes for extending single-label host names (host names containing no dots) to become
- fully qualified domain names (FQDNs). If a single-label host name is resolved on this interface, each of
- the specified search domains are appended to it in turn, converting it into a fully qualified domain name,
- until one of them may be successfully resolved.</para>
-
- <para>The specified domains are also used for routing of DNS queries: look-ups for host names ending in the
- domains specified here are preferably routed to the DNS servers configured for this interface. If a domain
- name is prefixed with <literal>~</literal>, the domain name becomes a pure "routing" domain, the DNS server
- is used for the given domain names only and is not used in the described domain search logic. By specifying a
- routing domain of <literal>~.</literal> (the tilde indicating definition of a routing domain, the dot
- referring to the DNS root domain which is the implied suffix of all valid DNS names) it is possible to
- route all DNS traffic preferably to the DNS server specified for this interface. The route domain logic is
- particularly useful on multi-homed hosts with DNS servers serving particular private DNS zones on each
- interface.</para>
+ <para>A list of domains which should be resolved using the DNS servers on this link. Each item in the list
+ should be a domain name, optionally prefixed with a tilde (<literal>~</literal>). The domains with the
+ prefix are called "routing-only domains". The domains without the prefix are called "search domains" and
+ are first used as search suffixes for extending single-label host names (host names containing no dots) to
+ become fully qualified domain names (FQDNs). If a single-label host name is resolved on this interface,
+ each of the specified search domains are appended to it in turn, converting it into a fully qualified
+ domain name, until one of them may be successfully resolved.</para>
+
+ <para>Both "search" and "routing-only" domains are used for routing of DNS queries: look-ups for host names
+ ending in those domains (hence also single label names, if any "search domains" are listed), are routed to
+ the DNS servers configured for this interface. The domain routing logic is particularly useful on
+ multi-homed hosts with DNS servers serving particular private DNS zones on each interface.</para>
+
+ <para>The "routing-only" domain <literal>~.</literal> (the tilde indicating definition of a routing domain,
+ the dot referring to the DNS root domain which is the implied suffix of all valid DNS names) has special
+ effect. It causes all DNS traffic which does not match another configured domain routing entry to be routed
+ to DNS servers specified for this interface. This setting is useful to prefer a certain set of DNS servers
+ if a link on which they are connected is available.</para>
<para>This setting is read by
- <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
+ <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+ "Search domains" correspond to the <varname>domain</varname> and <varname>search</varname> entries in
+ <citerefentry><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ Domain name routing has no equivalent in the traditional glibc API, which has no concept of domain
+ name servers limited to a specific link.</para>
</listitem>
</varlistentry>
<varlistentry>