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| author | Lennart Poettering <lennart@poettering.net> | 2016-02-23 18:24:03 +0100 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2016-02-23 18:26:35 +0100 |
| commit | 9053aaad4255a1d01a50f8e44784cd7eebe8f95c (patch) | |
| tree | d1692fca63166065b9e6e9c56715f509a5b9e1df /man/nss-resolve.xml | |
| parent | 45bd4854540ae50586e6bfcef5a153c4c1e2aca7 (diff) | |
| download | systemd-9053aaad4255a1d01a50f8e44784cd7eebe8f95c.tar.gz | |
man: change recommended order of NSS modules in /etc/nsswitch.conf
So far we recommended placing "nss-mymachines" after "nss-resolve" in the order
of preference in /etc/nsswitch.conf. This change reverse this order.
Rationale: single-label names are resolved via LLMNR by resolved, which has to
time out if no peer by that name exists. By placing "nss-mymachines" first
(which always responds immediately) we avoid running into this timeout for most
containers. Both modules should return the same data if LLMNR is used by the
container anyway.
While we are at it, improve the man pages of the three NSS modules in other
ways a bit.
Diffstat (limited to 'man/nss-resolve.xml')
| -rw-r--r-- | man/nss-resolve.xml | 45 |
1 files changed, 19 insertions, 26 deletions
diff --git a/man/nss-resolve.xml b/man/nss-resolve.xml index 8b0928145f..d9e56453e8 100644 --- a/man/nss-resolve.xml +++ b/man/nss-resolve.xml @@ -56,37 +56,36 @@ <refsect1> <title>Description</title> - <para><command>nss-resolve</command> is a plugin module for the - GNU Name Service Switch (NSS) functionality of the GNU C Library - (<command>glibc</command>) enabling it to resolve host names via - the - <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry> - local network name resolution service.</para> - - <para>To activate the NSS module, <literal>resolve</literal> - has to be added to the line starting with - <literal>hosts:</literal> in - <filename>/etc/nsswitch.conf</filename>.</para> - - <para>It is recommended to place <literal>resolve</literal> early - in the <filename>nsswitch.conf</filename> line (but after the - <literal>files</literal> entry), replacing the - <literal>dns</literal> entry if it exists, to ensure DNS queries - are always routed via + <para><command>nss-resolve</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the + GNU C Library (<command>glibc</command>) enabling it to resolve host names via the + <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry> local network + name resolution service. It replaces the <command>nss-dns</command> plug-in module that traditionally resolves + hostnames via DNS.</para> + + <para>To activate the NSS module, add <literal>resolve</literal> to the line starting with + <literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para> + + <para>It is recommended to place <literal>resolve</literal> early in <filename>/etc/nsswitch.conf</filename>' + <literal>hosts:</literal> line (but after the <literal>files</literal> or <literal>mymachines</literal> entries), + replacing the <literal>dns</literal> entry if it exists, to ensure DNS queries are always routed via <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + + <para>Note that <command>nss-resolve</command> will chain-load <command>nss-dns</command> if + <filename>systemd-resolved.service</filename> is not running, ensuring that basic DNS resolution continues to work + if the service is down.</para> </refsect1> <refsect1> <title>Example</title> - <para>Here is an example <filename>/etc/nsswitch.conf</filename> - file that enables <command>resolve</command> correctly:</para> + <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables <command>nss-resolve</command> + correctly:</para> <programlisting>passwd: compat mymachines group: compat mymachines shadow: compat -hosts: files <command>resolve</command> mymachines myhostname +hosts: files mymachines <command>resolve</command> myhostname networks: files protocols: db files @@ -96,12 +95,6 @@ rpc: db files netgroup: nis</programlisting> - <para>Note that <command>nss-resolve</command> will chain-load - <command>nss-dns</command> if - <filename>systemd-resolved.service</filename> is not running, - ensuring that basic DNS resolution continues to work if the - service is down.</para> - </refsect1> <refsect1> |