Internet Engineering Task Force A. Durand
Internet-Draft Juniper Networks
Intended status: BCP I. Gashinsky
Expires: July 23, 2011 Yahoo! Inc.
D. Lee
Facebook, Inc.
S. Sheppard
ATT Labs
January 19, 2011
Logging recommendations for Internet facing servers
draft-ietf-intarea-server-logging-recommendations-01
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 Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on July 23, 2011.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Recommendations . . . . . . . . . . . . . . . . . . . . . . . . 3
3. ISP Considerations . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative references . . . . . . . . . . . . . . . . . . . 5
6.2. Informative references . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5
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1. Introduction
According to the most recent predictions, the global IPv4 address
free pool at IANA will exhaust sometime in 2011. After that, service
providers will have a hard time finding enough IPv4 global addresses
to sustain product and subscriber growth. Due to the huge global
existing 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 but this is a years long perhaps
decades long process.
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
documents. All include some form of address translation/address
sharing, being NAT44, NAT64 or DS-Lite.
The effects on the Internet of the introduction of those address
sharing techniques have been documented in
[I-D.ietf-intarea-shared-addressing-issues].
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. Its does not provide any
recommendations about logging on carrier-grade NAT or other address
sharing tools.
2. Recommendations
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
It is RECOMMENDED as best current practice that Internet facing
servers logging incoming IP addresses also log:
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o The source port number.
o A timestamp, preferably in UTC, accurate to the second, from a
traceable time source (e.g. NTP).
o The transport protocol (usually TCP or UDP) and destination port
number, when the server application is defined to use multiple
transports or multiple ports.
Discussion: Carrier-grade NATs may have different policies to recycle
ports, some implementations may decide to reuse ports almost
immediately, some may wait several minutes before marking the port
ready for reuse. As a result, servers have no idea how fast the
ports will be reused and, thus, should log timestamps using a
reasonably accurate clock. At this point the RECOMMENDED accuracy
for timestamps is to the second or better. Representation of
timestamps in UTC is preffered to localtime with UTC-offset or time
zone as this extra information can be lost in the reporting chain.
Examples of Internet facing servers include, but are not limited to,
web servers and email servers.
Although the deployment of address sharing techniques is not
immediately foreseen in IPv6, the above recommendations apply to both
IPv4 and IPv6, if only for consistency and code simplification
reasons.
Discussions about data retention policies are out of scope for this
document.
The above recommendation also applies to devices such as load-
balancers logging incoming connections on behalf of actual servers.
3. ISP Considerations
ISP deploying IP address sharing techniques should also deploy a
corresponding logging architecture to maintain records of the
relation between customers identity and IP/port resources they
utilize. However, recommendation on this topic are out of scope for
this document.
4. IANA Considerations
None.
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5. Security Considerations
In the absence of source port number and accurate timestamp,
operators deploying any address sharing techniques will not be able
to identify unambiguously customers when dealing with abuse or public
safety queries.
6. References
6.1. Normative references
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
6.2. Informative references
[I-D.ietf-intarea-shared-addressing-issues]
Ford, M., Boucadair, M., Durand, A., Levis, P., and P.
Roberts, "Issues with IP Address Sharing",
draft-ietf-intarea-shared-addressing-issues-02 (work in
progress), October 2010.
Authors' Addresses
Alain Durand
Juniper Networks
1194 North Mathilda Avenue
Sunnyvale, CA 94089-1206
USA
Email: adurand@juniper.net
Igor Gashinsky
Yahoo! Inc.
45 West 18th St.
New York, NY 10011
USA
Email: igor@yahoo-inc.com
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Donn Lee
Facebook, Inc.
1601 S. California Ave.
Palo Alto, CA 94304
USA
Email: donn@fb.com
Scott Sheppard
ATT Labs
575 Morosgo Ave, 4d57
Atlanta, GA 30324
USA
Email: Scott.Sheppard@att.com
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