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-<!-- This document was created with Syntext Serna Free. --><chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US" xml:id="configuringlnet">
+<!-- This document was created with Syntext Serna Free. -->
+<chapter xmlns="http://docbook.org/ns/docbook"
+ xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US"
+ xml:id="configuringlnet">
<title xml:id="configuringlnet.title">Configuring Lustre Networking (LNet)</title>
<para>This chapter describes how to configure Lustre Networking (LNet). It
includes the following sections:</para>
global:
numa_range: 0
max_intf: 200
- discovery: 1</screen>
+ discovery: 1
+ drop_asym_route: 0</screen>
</section>
<section xml:id="lnet_config.lnetaddshowdelete">
<title><indexterm><primary>LNet</primary>
> lnetctl set small_buffers 0
> lnetctl set large_buffers 0</screen>
</section>
+ <section condition='l2D' xml:id="lnet_config.asym_route">
+ <title><indexterm>
+ <primary>LNet</primary>
+ <secondary>cli</secondary>
+ <tertiary>asymmetrical route</tertiary>
+ </indexterm>Asymmetrical Routes</title>
+ <section xml:id="lnet_config.asym_route.overview">
+ <title>Overview</title>
+ <para>An asymmetrical route is when a message from a remote peer is
+ coming through a router that is not known by this node
+ to reach the remote peer.</para>
+ <para>Asymmetrical routes can be an issue when debugging network, and
+ allowing them also opens the door to attacks where hostile clients
+ inject data to the servers.</para>
+ <para>So it is possible to activate a check in LNet, that will detect
+ any asymmetrical route message and drop it.</para>
+ </section>
+ <section xml:id="lnet_config.dynamic_discovery.configuration">
+ <title>Configuration</title>
+ <para>In order to switch asymmetric route detection on or off, the
+ following command is used:</para>
+ <screen>lnetctl set drop_asym_route [0 | 1]</screen>
+ <para>This command works on a per-node basis. This means each node in a
+ Lustre cluster can decide whether it accepts asymmetrical route
+ messages.</para>
+ <para>To check the current <literal>drop_asym_route</literal> setting, the
+ <literal>lnetctl global show</literal> command can be used as shown in
+ <xref linkend="lnet_config.show_global_settings"/>.</para>
+ <para>By default, asymmetric route detection is off.</para>
+ </section>
+ </section>
<section>
<title><indexterm>
<primary>LNet</primary>
</section>
</section>
</chapter>
+<!--
+ vim:expandtab:shiftwidth=2:tabstop=8:
+ -->