Repository :
http://git.fedorahosted.org/cgit/docs/networking-guide.git
On branch : master
---------------------------------------------------------------
commit e09c199bede672b90c1ba5b0d77418fd98774ac2
Author: Stephen Wadeley <swadeley(a)redhat.com>
Date: Thu Jul 17 22:24:49 2014 +0200
Add "Recommended Naming Practices"
---------------------------------------------------------------
en-US/Configure_Host_Names.xml | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/en-US/Configure_Host_Names.xml b/en-US/Configure_Host_Names.xml
index ff476ad..8ff5989 100644
--- a/en-US/Configure_Host_Names.xml
+++ b/en-US/Configure_Host_Names.xml
@@ -16,10 +16,17 @@
The <quote>static</quote> host name is the traditional <systemitem
class="systemname">hostname</systemitem>, which can be chosen by the
user, and is stored in the <filename>/etc/hostname</filename> file. The
<quote>transient</quote> <systemitem
class="systemname">hostname</systemitem> is a dynamic host name
maintained by the kernel. It is initialized to the static host name by default, whose
value defaults to <quote>localhost</quote>. It can be changed by
<systemitem class="protocol">DHCP</systemitem> or <systemitem
class="protocol">mDNS</systemitem> at runtime. The
<quote>pretty</quote> <systemitem
class="systemname">hostname</systemitem> is a free-form UTF8 host name
for presentation to the user.
<note>
<para>
- A host name can be a free-form string up to 64 characters in length, however it
is recommended that the static and transient names consists only of 7 bit ASCII lower-case
characters, no spaces or dots, and limits itself to the format allowed for <systemitem
class="protocol">DNS</systemitem> domain name labels, even though this
is not a strict requirement. The <application>hostnamectl</application> tool
will enforce the following: Static and transient host names to consist of
<literal>a-z</literal>, <literal>A-Z</literal>,
<literal>0-9</literal>,
<quote><literal>-</literal></quote>,
<quote><literal>_</literal></quote> and
<quote><literal>.</literal></quote> only, to not begin or end in a
dot, and to not have two dots immediately following each other. The size limit of 64
characters is enforced.
+ A host name can be a free-form string up to 64 characters in length. However,
Red Hat recommends that both static and transient names match the
<firstterm>fully-qualified domain name</firstterm>
(<acronym>FQDN</acronym>) used for the machine in <systemitem
class="protocol">DNS</systemitem>, such as <systemitem
class="domainname">host.example.com</systemitem>. It is also
recommended that the static and transient names consists only of 7 bit ASCII lower-case
characters, no spaces or dots, and limits itself to the format allowed for <systemitem
class="protocol">DNS</systemitem> domain name labels, even though this
is not a strict requirement. Older specifications do not permit the underscore, and so
their use is not recommended.</para>
+ <para>The <application>hostnamectl</application> tool will
enforce the following: Static and transient host names to consist of
<literal>a-z</literal>, <literal>A-Z</literal>,
<literal>0-9</literal>,
<quote><literal>-</literal></quote>,
<quote><literal>_</literal></quote> and
<quote><literal>.</literal></quote> only, to not begin or end in a
dot, and to not have two dots immediately following each other. The size limit of 64
characters is enforced.
</para>
</note>
</para>
+ <section id="sec-Recommended_Naming_Practices">
+ <title>Recommended Naming Practices</title>
+ <para>
+ The Internet Corporation for Assigned Names and Numbers (ICANN) sometimes adds
previously unregistered Top-Level Domains (such as <systemitem
class="domainname">.yourcompany</systemitem>) to the public register.
Therefore, Red Hat strongly recommends that you do not use a domain name that is
not delegated to you, even on a private network, as this can result in a domain name that
resolves differently depending on network configuration. As a result, network resources
can become unavailable. Using domain names that are not delegated to you also makes DNSSEC
more difficult to deploy and maintain, as domain name collisions require manual
configuration to enable DNSSEC validation. See the <ulink
url="http://www.icann.org/en/help/name-collision/faqs">ICANN FAQ on domain
name collision</ulink> for more information on this issue.
+ </para>
+ </section>
</section>
<!-- Topics, Tasks -->
<section id="sec_Configuring_Host_Names_Using_hostnamectl">