\section{Introduction}

This document provides information about the diagnostics of White Rabbit
switches. It is a complementary documentation to the official \emph{White Rabbit
Switch: User's Manual} published with every stable firmware release. Please
refer to this user manual for a basic information about the switch and
guidelines on its configuration.\\

White Rabbit Switch firmware starting from \emph{v4.2} provides diagnostic
mechanisms in the form of SNMP objects and Syslog messages. This document is
organized in two parts. It starts with a description of the SNMP objects and
procedures to be followed if various errors are reported (section
\ref{sec:snmp_exports}). This first part is meant for the operators and people
integrating a WR switch into a control system, without the deep knowledge about
the White Rabbit internals. These people usually have to perform a quick
diagnostics and decide on actions to restore a WR network.
Second part of the document tries to list all the possible failures
that may disturb synchronization and Ethernet switching (section
\ref{sec:failures}). It is meant for the WR experts to help them with in-depth
diagnosis of the problems reported by SNMP.

This document has many internal hyperlinks that associate general SNMP status
objects and expert SNMP objects with related problems' description and the other
way round. These links can be easily used when reading the document on a
computer.
