Logging Recommendations for Internet-Facing Servers
RFC 6302

Internet Engineering Task Force (IETF)                         A. Durand
Request for Comments: 6302                              Juniper Networks
BCP: 162                                                    I. Gashinsky
Category: Best Current Practice                              Yahoo! Inc.
ISSN: 2070-1721                                                   D. Lee
                                                          Facebook, Inc.
                                                             S. Sheppard
                                                                ATT Labs
                                                               June 2011

          Logging Recommendations for Internet-Facing Servers

Abstract

   In the wake of IPv4 exhaustion and deployment of IP address sharing
   techniques, this document recommends that Internet-facing servers log
   port number and accurate timestamps in addition to the incoming IP
   address.

Status of This Memo

   This memo documents an Internet Best Current Practice.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   BCPs is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6302.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Durand, et al.            Best Current Practice                 [Page 1]
RFC 6302             Internet-Facing Server Logging            June 2011

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
   2.  Recommendations . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  ISP Considerations  . . . . . . . . . . . . . . . . . . . . . . 4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 4
     5.1.  Normative references  . . . . . . . . . . . . . . . . . . . 4
     5.2.  Informative references  . . . . . . . . . . . . . . . . . . 4

1.  Introduction

   The global IPv4 address free pool at IANA was exhausted in February
   2011.  Service providers will now have a hard time finding enough
   IPv4 global addresses to sustain product and subscriber growth.  Due
   to the huge existing global infrastructure, both hardware and
   software, vendors, and service providers must continue to support
   IPv4 technologies for the foreseeable future.  As legacy applications
   and hardware are retired, the reliance on IPv4 will diminish;
   however, this is a process that will take years, perhaps decades.

   To maintain legacy IPv4 address support, service providers will have
   little choice but to share IPv4 global addresses among multiple
   customers.  Techniques to do so are outside of the scope of this
   document.  All include some form of address translation/address
   sharing, being NAT44 [RFC3022], NAT64 [RFC6146] or DS-Lite [DS-LITE].

   The effects on the Internet of the introduction of those address
   sharing techniques have been documented in [RFC6269].

   Address sharing techniques come with their own logging infrastructure
   to track the relation between which original IP address and source
   port(s) were associated with which user and external IPv4 address at
   any given point in time.  In the past, to support abuse mitigation or
   public safety requests, the knowledge of the external global IP
   address was enough to identify a subscriber of interest.  With
   address sharing technologies, only providing information about the
   external public address associated with a session to a service
   provider is no longer sufficient information to unambiguously
   identify customers.

   Note: This document provides recommendations for Internet-facing
   servers logging incoming connections.  It does not provide any
   recommendations about logging on carrier-grade NAT or other address
   sharing tools.