Transmission of Syslog Messages over UDP
RFC 5426

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Network Working Group                                       A. Okmianski
Request for Comments: 5426                           Cisco Systems, Inc.
Category: Standards Track                                     March 2009

                Transmission of Syslog Messages over UDP

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

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Abstract

   This document describes the transport for syslog messages over UDP/
   IPv4 or UDP/IPv6.  The syslog protocol layered architecture provides
   for support of any number of transport mappings.  However, for
   interoperability purposes, syslog protocol implementers are required
   to support this transport mapping.

Okmianski                   Standards Track                     [Page 1]
RFC 5426                  Syslog UDP Transport                March 2009

Table of Contents

   1. Introduction ....................................................2
   2. Conventions Used in This Document ...............................3
   3. Transport Protocol ..............................................3
      3.1. One Message Per Datagram ...................................3
      3.2. Message Size ...............................................3
      3.3. Source and Target Ports ....................................4
      3.4. Source IP Address ..........................................4
      3.5. UDP/IP Structure ...........................................4
      3.6. UDP Checksums ..............................................4
   4. Reliability Considerations ......................................5
      4.1. Lost Datagrams .............................................5
      4.2. Message Corruption .........................................5
      4.3. Congestion Control .........................................5
      4.4. Sequenced Delivery .........................................5
   5. Security Considerations .........................................6
      5.1. Sender Authentication and Message Forgery ..................6
      5.2. Message Observation ........................................7
      5.3. Replaying ..................................................7
      5.4. Unreliable Delivery ........................................7
      5.5. Message Prioritization and Differentiation .................7
      5.6. Denial of Service ..........................................8
   6. IANA Considerations .............................................8
   7. Acknowledgements ................................................8
   8. References ......................................................8
      8.1. Normative References .......................................8
      8.2. Informative References .....................................9

1.  Introduction

   Informational RFC 3164 [8] describes the syslog protocol as it was
   observed in existing implementations.  It describes both the format
   of syslog messages and a UDP [1] transport.  Subsequently, a
   Standards-Track syslog protocol has been defined in RFC 5424 [2].

   RFC 5424 specifies a layered architecture that provides for support
   of any number of transport layer mappings for transmitting syslog
   messages.  This document describes the UDP transport mapping for the
   syslog protocol.

   The transport described in this document can be used for transmitting
   syslog messages over both IPv4 [3] and IPv6 [4].

Okmianski                   Standards Track                     [Page 2]
RFC 5426                  Syslog UDP Transport                March 2009