man: update explanation about the format to specify DNS servers

3 files changed, 32 insertions, 14 deletions

diff --git a/man/resolvectl.xml b/man/resolvectl.xml
index 0ae70dc34b..a4bd8f52d7 100644
--- a/man/resolvectl.xml
+++ b/man/resolvectl.xml
@@ -145,15 +145,20 @@
           settings for network interfaces. These commands may be used to inform
           <command>systemd-resolved</command> or <command>systemd-networkd</command> about per-interface DNS
           configuration determined through external means. The <command>dns</command> command expects IPv4 or
-          IPv6 address specifications of DNS servers to use. The <command>domain</command> command expects
-          valid DNS domains, possibly prefixed with <literal>~</literal>, and configures a per-interface
-          search or route-only domain. The <command>default-route</command> command expects a boolean
-          parameter, and configures whether the link may be used as default route for DNS lookups, i.e. if it
-          is suitable for lookups on domains no other link explicitly is configured for. The
-          <command>llmnr</command>, <command>mdns</command>, <command>dnssec</command> and
-          <command>dnsovertls</command> commands may be used to configure the per-interface LLMNR,
-          MulticastDNS, DNSSEC and DNSOverTLS settings. Finally, <command>nta</command> command may be used
-          to configure additional per-interface DNSSEC NTA domains.</para>
+          IPv6 address specifications of DNS servers to use. Each address can optionally take a port number
+          separated with <literal>:</literal>, a network interface name or index separated with
+          <literal>%</literal>, and a Server Name Indication (SNI) separated with <literal>#</literal>. When
+          IPv6 address is specified with a port number, then the address must be in the square brackets. That
+          is, the acceptable full formats are <literal>111.222.333.444:9953%ifname#example.com</literal> for
+          IPv4 and <literal>[1111:2222::3333]:9953%ifname#example.com</literal> for IPv6. The
+          <command>domain</command> command expects valid DNS domains, possibly prefixed with
+          <literal>~</literal>, and configures a per-interface search or route-only domain. The
+          <command>default-route</command> command expects a boolean parameter, and configures whether the
+          link may be used as default route for DNS lookups, i.e. if it is suitable for lookups on domains no
+          other link explicitly is configured for. The <command>llmnr</command>, <command>mdns</command>,
+          <command>dnssec</command> and <command>dnsovertls</command> commands may be used to configure the
+          per-interface LLMNR, MulticastDNS, DNSSEC and DNSOverTLS settings. Finally, <command>nta</command>
+          command may be used to configure additional per-interface DNSSEC NTA domains.</para>
 
           <para>Commands <command>dns</command>, <command>domain</command> and <command>nta</command> can take
           a single empty string argument to clear their respective value lists.</para>
diff --git a/man/resolved.conf.xml b/man/resolved.conf.xml
index 0e7a9f4bc6..535a23f500 100644
--- a/man/resolved.conf.xml
+++ b/man/resolved.conf.xml
@@ -47,8 +47,13 @@
 
       <varlistentry>
         <term><varname>DNS=</varname></term>
-        <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as system DNS servers. DNS requests
-        are sent to one of the listed DNS servers in parallel to suitable per-link DNS servers acquired from
+        <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as system DNS servers. Each address can
+        optionally take a port number separated with <literal>:</literal>, a network interface name or index separated with
+        <literal>%</literal>, and a Server Name Indication (SNI) separated with <literal>#</literal>. When IPv6 address is
+        specified with a port number, then the address must be in the square brackets. That is, the acceptable full formats
+        are <literal>111.222.333.444:9953%ifname#example.com</literal> for IPv4 and
+        <literal>[1111:2222::3333]:9953%ifname#example.com</literal> for IPv6. DNS requests are sent to one of the listed
+        DNS servers in parallel to suitable per-link DNS servers acquired from
         <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> or
         set at runtime by external applications.  For compatibility reasons, if this setting is not specified, the DNS
         servers listed in <filename>/etc/resolv.conf</filename> are used instead, if that file exists and any servers
@@ -57,8 +62,8 @@
 
       <varlistentry>
         <term><varname>FallbackDNS=</varname></term>
-        <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as the fallback DNS servers. Any
-        per-link DNS servers obtained from
+        <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as the fallback DNS servers. Please see
+        <varname>DNS=</varname> for acceptable format of adddresses. Any per-link DNS servers obtained from
         <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
         take precedence over this setting, as do any servers set via <varname>DNS=</varname> above or
         <filename>/etc/resolv.conf</filename>. This setting is hence only used if no other DNS server information is
diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 58d1f2c717..0b0c751e91 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -606,7 +606,15 @@
             <para>A DNS server address, which must be in the format
             described in
             <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
-            This option may be specified more than once. This setting is read by
+            This option may be specified more than once. Each address can optionally take a port number
+            separated with <literal>:</literal>, a network interface name or index separated with
+            <literal>%</literal>, and a Server Name Indication (SNI) separated with <literal>#</literal>.
+            When IPv6 address is specified with a port number, then the address must be in the square
+            brackets. That is, the acceptable full formats are
+            <literal>111.222.333.444:9953%ifname#example.com</literal> for IPv4 and
+            <literal>[1111:2222::3333]:9953%ifname#example.com</literal> for IPv6. This setting can be
+            specified multiple times. If an empty string is assigned, then the all previous assignments
+            are cleared. This setting is read by
             <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
           </listitem>
         </varlistentry>