OPSEC Working Group (proposed) G. Jones
Internet-Draft The MITRE Corporation
Expires: October 20, 2004 April 21, 2005 R. Callon
Juniper Networks
M. Kaeo
Double Shot Security
April
October 21, 2004

Framework for Operational Security Requirements Capabilities for IP Network
Infrastructure
draft-jones-opsec-framework-00
draft-jones-opsec-framework-01

Status of this Memo

This document is an Internet-Draft and is subject to all provisions
of section 3 of RFC 3667. By submitting this Internet-Draft, I certify each
author represents that any applicable patent or other IPR claims of
which I am he or she is aware have been or will be disclosed, and any of
which I he or she become aware will be disclosed, in accordance with
RFC 3668.

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."

The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.

The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.

This Internet-Draft will expire on October 20, 2004. April 21, 2005.

Abstract

This document outlines work to be done and documents to be produced
by the proposed Operational Security Requirements Capabilities (OPSEC) Working Group. The
goal of the working group is to codify knowledge gained through

Jones, et al. Expires April 21, 2005 [Page 1]

Internet-Draft OpSec Framework October 2004

operational experience about feature sets that are required needed to securely
deploy and operate managed network elements providing transit
services at OSI layers 2 and 3,

Jones, et al. Expires October 20, 2004 [Page 1]

Internet-Draft OpSec Framework April 2004

i.e. switches the data link and routers. IP layers. The intent is to provide
clear, concise documentation of requirements capabilities necessary for operating
networks securely, to assist network operators in communicating their
requirements to vendors, and to provide vendors with input that is
useful for building more secure devices. The working group will
produce requirements a list of capabilities appropriate for large Internet Service
Provider (ISP) and Enterprise Networks. This work is intended to
refine
RFCxxxx. [RFC3871].

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 . 4
1.1 Goals . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . 3 4
1.3 Scope . . Threat Model . . . . . . . . . . . . . . . . . . . . . . . 4
1.3.1 Threats Addressed, Threats Not Addressed . 3
1.4 Intended Audience . . . . . . 4
1.3.2 Active, Passive and Combined Attacks . . . . . . . . . 5
1.3.3 Categories of Threats . . . . . 4
1.5 Format and Definition of Requirements . . . . . . . . . . 4
1.6 Applicability . 5
1.3.4 Threat Sources . . . . . . . . . . . . . . . . . . . . 6
1.4 Attacks . 5
1.7 Intended Use . . . . . . . . . . . . . . . . . . . . . . . 5
1.8 Definitions . 6
1.4.1 Passive attacks . . . . . . . . . . . . . . . . . . . 6
1.4.2 Eavesdropping/Sniffing . . . 6
2. Documents . . . . . . . . . . . . . 6
1.4.3 Off-line Cryptographic Attacks . . . . . . . . . . . . 10
2.1 Standards Survey (info) 7
1.4.4 Active Attacks . . . . . . . . . . . . . . . . . 10
2.2 In-Band management requirements (BCP) . . . 7
1.4.5 Replay Attacks . . . . . . . 10
2.3 Out-of-Band management requirements (BCP) . . . . . . . . 11
2.4 Filtering requirements (BCP) . . . . . 7
1.4.6 Message Insertion . . . . . . . . . . 11
2.5 Event Logging Requirements document (BCP) . . . . . . . . 11
2.6 Configuration and Management Interface Requirements
(BCP) 7
1.4.7 Message Modification . . . . . . . . . . . . . . . . . 8
1.4.8 Message Deletion . . . . . . . . . 12
2.7 AAA requirements document (BCP) . . . . . . . . . . 8
1.4.9 Man-In-The-Middle . . . 12
2.8 Documentation and Assurance requirements document (BCP) . 12
2.9 Miscellaneous requirements document (BCP) . . . . . . . . 12
2.10 Large ISP Operational Security Requirements Profile
(info) . . . . . . 8
1.5 Scope . . . . . . . . . . . . . . . . . . . 13
2.11 Large Enterprise Operational Security Requirements
Profile (info) . . . . . . . 8
1.6 Intended Audience . . . . . . . . . . . . . . 13
2.12 OPSEC Deliberation Summary document (info) . . . . . . 9
1.7 Format and Definition of Capabilities . 13
3. Security Considerations . . . . . . . . . 9
1.8 Applicability . . . . . . . . . 14
4. References . . . . . . . . . . . . . 10
1.9 Intended Use . . . . . . . . . . . . 15
4.1 Normative References . . . . . . . . . . . 11
1.10 Definitions . . . . . . . . . 15
4.2 Non-normative References . . . . . . . . . . . . . . 11
2. Documents . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 16
A. Acknowledgments . 15
2.1 Standards Survey (info) . . . . . . . . . . . . . . . . . 15
2.2 In-Band management capabilities (BCP) . . . . . . . . . . 15
2.3 Out-of-Band management capabilities (BCP) . . . . . . . . 16
2.4 Filtering capabilities (BCP) . . . . . . . . . . . . . . . 16
2.5 Event Logging Capabilities document (BCP) . . . . . . . . 16
2.6 Configuration and Management Interface Capabilities
(BCP) . . . . . 17
Intellectual Property and Copyright Statements . . . . . . . . . . . . . . . . . . . . . 17
2.7 AAA capabilities document (BCP) . . . . . . . . . . . . . 17
2.8 Documentation and Assurance capabilities document (BCP) . 17
2.9 Miscellaneous capabilities document (BCP) . . . . . . . . 18

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 2]

Internet-Draft OpSec Framework April October 2004

1. Introduction

1.1 Goals

The goal

2.10 Large ISP Operational Security Capabilities Profile
(info) . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.11 Large Enterprise Operational Security Capabilities
Profile (info) . . . . . . . . . . . . . . . . . . . . . . 18
2.12 OPSEC Deliberation Summary document (info) . . . . . . . . 18
3. Security Considerations . . . . . . . . . . . . . . . . . . . 19
4. Normative References . . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 20
A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 21
Intellectual Property and Copyright Statements . . . . . . . . 22

Jones, et al. Expires April 21, 2005 [Page 3]

Internet-Draft OpSec Framework October 2004

1. Introduction

1.1 Goals

The goal of the Operational Security Working Group is to codify
knowledge gained through operational experience about feature sets
that are needed to securely deploy and operate managed network
elements providing transit services at the data link and IP layers.

It is anticipated that the codification of this knowledge will be an
aid to vendors in producing more securable network elements, and an
aid to operators in increasing security by deploying and configuring
more secure network elements.

This framework document provides an overview of the work to be done
by the working group, and describes the documents to be produced in
this effort.

1.2 Motivation

Network operators need the appropriate feature sets and tools on
their infrastructure devices to ensure that they can effectively
deploy and manage their networks securely while maintaining the
ability to provide reliable service to their customers. Vendors need
guidelines on which security features and functionality are critical
for operators to be able to reach that goal.

1.3 Threat Model

1.3.1 Threats Addressed, Threats Not Addressed

This section describes the general classes of threats that this work
intends to address. Specific threats and attacks will be discussed
in the documents which are referred to in this framework. Each of
those documents will enumerate the capabilities which are required to
mitigate the risk of these specific threats.

The intent is to address real-world threats to and attacks on network
infrastructure devices which have severely impacted network
operations or have immediate potential to do so. The intent is NOT
to build a complete theoretical threat model or list every possible
attack.

The threats will be limited to those that affect the management of
network infrastructure and its ability to transit traffic. Threats
to the confidentiality and integrity of transit traffic will not be
addressed.

Jones, et al. Expires April 21, 2005 [Page 4]

Internet-Draft OpSec Framework October 2004

1.3.2 Active, Passive and Combined Attacks

[RFC3552] describes a general Internet threat model which readers of
this document should be familiar with. It defines a threat model to
describes the capabilities that an attacker is assumed to be able to
deploy against a resource. [RFC3552] classifies attacks into two
main categories: passive attacks and active attacks. Passive attacks
are ones where an attacker simply reads information off the network
and obtains confidential and/or private information which can be used
to compromise network systems. Active attacks are ones where the
attacker writes data to the network and can include replay attacks,
message insertion, message deletion, message modification and
man-in-the-middle attacks. Often, these passive and active attacks
are combined. For example, routing information is diverted via a
man-in-the-middle attack to force confidential information to transit
a network path on which the attacker is able to perform
eavesdropping.

1.3.3 Categories of Threats

The following sections provide a model that can be used to further
categorize attacks on infrastructure devices and/or the operating
behavior of these devices, and also gives some examples of attacks
which fall into each classification.

It is common to categorize threats based on the effects or damage
caused by associated attacks. For example, threats generally fall
under one of the three categories as defined in [RFC2196]:

o Unauthorized access to resources and/or information
o Unintended and/or unauthorized disclosure of information
o Denial of service

There are a number of attacks, any one of which, if exploited, can
lead to any of the above mentioned threats. As one example, if an
intruder has taken control of a router (for example by guessing the
password) then he could potentially obtain unauthorized access to
resources, could gain unauthorized disclosure of information, and
could also deny service to legitimate users. This method of
categorizing threats based on the result of the threat therefore
results in categories which are orthogonal to the cause of the
effect, and thus orthogonal to the device capabilities which are
needed.

Categorization of attacks based on the capabilities required to mount
the attack will allow the analysis and description of the attacks to
be more closely aligned with the product capabilities required to
defeat or mitigate the attack.

Jones, et al. Expires April 21, 2005 [Page 5]

Internet-Draft OpSec Framework October 2004

1.3.4 Threat Sources

The sources of threats in an operational network take many forms.
Some sources can be intentional, such as a malicious intruder
actively gaining access to an unauthorized resource or causing a
denial of service attack. Other sources can be unintentional but
still render the network unusable, such as software bugs or
configuration mistakes. Many of the unintentional threat sources can
be difficult to recognize or prevent. However wherever possible,
capabilities and functionality will be defined which minimize the
extent of the damage done under these circumstances.

Threats can originate from outside or inside and can be due to
vulnerabilities in a device or weaknesses in operational processes.
Inside threats pertain to an authorized participant in the operation
of the network performing unauthorized actions. Outside threats
pertain to any unauthorized network devices or person causing havoc
with normal network operations.

On Path network devices are able to read, modify, or remove any
datagram transmitted along a given path. Off-path hosts can transmit
arbitrary datagrams that appear to come from any hosts but cannot
necessarily receive datagrams intended for other hosts.

1.4 Attacks

This section specifies attack categories based on the capabilities
required to mount the attack and provides more granular detail of
many of the identifiable and recognized threats to which network
infrastructure devices are susceptible.

1.4.1 Passive attacks

Passive attacks are ones where an attacker simply reads information
off the network and obtains confidential and/or private information
which can be used to compromise network systems.

1.4.2 Eavesdropping/Sniffing

The most common form of passive attack is eavesdropping, where the
attacker is able to read the data which is being transmitted from the
sender to the receiver. In any operational network, the entire data
path and every device involved in the data path must be considered
for this type of attack. Any information which could be used to
potentially gain unauthorized access to a device or is private must
be protected. This includes passwords, configuration files and log
files. It is common to think only of protecting the data path and to
make sure that data is not diverted along a different path which may

Jones, et al. Expires April 21, 2005 [Page 6]

Internet-Draft OpSec Framework October 2004

be easier to eavesdrop on, such as a wireless network. In many
instances it would be wise to consider cryptographically protecting
data confidentiality wherever sensitive information is involved.

1.4.3 Off-line Cryptographic Attacks

These attacks typically capture some data which has been
cryptographically protected and then use varying means to try and
recover the original data. Poor password protection protocols can
easily be reverse engineered and poorly chosen passwords can also be
easily deciphered. As described in [RFC3552], a number of popular
password-based challenge response protocols are vulnerable to a
dictionary attack. The attacker captures a challenge-response pair
and then proceeds to try entries from a list of common words (such as
a dictionary file) until he finds a password that produces the right
response.

1.4.4 Active Attacks

Active attacks are ones where the working group attacker writes data to the
network. Generally, any part of a data packet can be forged. When
the source IP address is forged, the attack is generally referred to provide
as a clear, concise
documentation spoofing attack. These attacks can be mitigated by filtering
traffic based on IP addresses to only allow legitimate traffic
to/from a network.

Not all active attacks require forged addresses and most systems are
susceptible to a number of operational security requirements common attack patterns which are described
in the next sections. Note that any type of active attack can be
used for Denial of Service if the
infrastructure traffic is sent at such a rate that
it exceeds a networks link capacity or exhausts device resources.

1.4.5 Replay Attacks

A replay attack is a combination of large IP networks, including routers and switches,
to equipment vendors, service providers, a passive and network operators.

This framework document provides an overview active attack.
In this type of attack, the work to be done
by attacker records some number of messages
off of the working group, wire and describes then plays them back to the documents original recipient.
Note that the attacker does not need to be produced in
this effort.

1.2 Motivation

Network operators need able to understand the appropriate feature sets and tools on
their infrastructure devices
messages. He merely needs to ensure that they can effectively
deploy capture and manage their networks securely while maintaining re-transmit them.

1.4.6 Message Insertion

In a message insertion attack, the
ability attacker forges one or more
messages and injects them into the network. Often these messages
will have a forged source address in order to provide reliable service disguise the identity
of the attacker.

Message insertion attacks can be used to their customers. Vendors need
guidelines on exploit known

Jones, et al. Expires April 21, 2005 [Page 7]

Internet-Draft OpSec Framework October 2004

vulnerabilities in protocol software. Routers and switches implement
protocols which security features in some cases make use of software which is well
known and widely deployed. Malicious attackers therefore may be
familiar with the protocol software and functionality are critical
for operators to be able to reach that goal. exploit known
vulnerabilities.

1.4.7 Message Modification

In a message modification attack, the attacker removes a message from
the wire, modifies it, and then resends it. The threats which contents of the
message may be modified and/or the intended recipient. [need example
specific to network infrastructure devices are most susceptible operations where this would be harmful]

1.4.8 Message Deletion

In a message deletion attack, the attacker simply removes a message
from the wire. [need example specific to encompass network operations where
this is harmful]

1.4.9 Man-In-The-Middle

A Man-In-The-Middle attack combines the following:
o unauthorized access above techniques in a special
form: The attacker subverts the communication stream in order to pose
as the device which can lead sender to portions of receiver and the network infrastructure receiver to be under malicious control
o denial the sender. This
differs fundamentally from the above forms of service attack because it
attacks where the device is rendered incapable identity of performing its intended function
o spoofing attacks where malicious packets can lead to network
traffic rerouting or network down-time

Many the communicating parties, rather than the
data stream itself. Consequently, many techniques which provide
integrity of these threats the communications stream are described in detail in [RFC2196].
[RFC3013] recommends security services and procedures for ISPs insufficient to protect
against man-in-the-middle attacks.

Man-in-the-middle attacks are possible whenever peer entity
authentication is not used. For example, it is trivial to mount
man-in-the-middle attacks on local networks via ARP spoofing where
the attacker forges an ARP with the victim's IP address and
provides his own
MAC address to gain access to a framework for discussion network. The attacker can then do
further damage by sending forged messages. Imagine if the victim^�s
IP address was that of security expectations. a tftp server. The
documents which will be described in this framework document will
complement these existing standards attacker could potentially
download invalid system images or configuration files to a network
device and will enumerate features which
are required subsequently compromise that network device.

[Ed. - Need to implement many of review existing capabilities. Do the policies threats and procedures
suggested in both.

1.3 Scope

The working group will produce requirements appropriate for:

o Internet Service Provider (ISP) Networks
o Enterprise Networks
attack types listed above cover them all ? Are there capabilities
that imply threats and attack classes not listed above]

1.5 Scope

The following classes of devices are excluded from the OPSEC working group charter at this time, and are therefore outside of the scope will produce a list of capabilities appropriate
for:

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 3] 8]

Internet-Draft OpSec Framework April October 2004

this document:

o Wireless devices

o SOHO devices
o Security devices (firewalls, IDS, Authentication Servers) Internet Service Provider (ISP) Networks
o Hosts Enterprise Networks

The following are explicitly out of scope:

o general purpose hosts that do not transit traffic including
infrastructure hosts such as name/time/log/AAA servers, etc.,
o unmanaged devices,
o customer managed devices (e.g. firewalls, Intrusion Detection
System, dedicated VPN devices, etc.),
o SOHO (Small Office, Home Office) devices (e.g. personal
firewalls, Wireless Access Points, Cable Modems, etc.),
o confidentiality of customer data,
o integrity of customer data,
o physical security.
This means that while

These limitations have been made to keep the requirements in amount of work and size
of documents manageable. While the minimum profile (and
others) capabilities listed here may apply, additional requirements
apply to systems outside the scope, no capabilities have not be been added
to account for their unique needs.

While the examples given are written with IPv4 in mind, most of the
requirements
capabilities are general enough to apply to IPv6.

1.4

1.6 Intended Audience

There are two intended audiences: the network operator who selects,
purchases, and operates IP network equipment, and the vendors who
create these devices.

1.5

1.7 Format and Definition of Requirements Capabilities

A separate document will be created for specific categories of
requirements.
capabilities. Each individual requirement capability will have the following
element:
Requirement

Capability (what)
The requirement capability describes a policy to be supported by the device.

For example, "The device MUST support secure channels that allow
in-band access to all management and configuration functions."
Requirements

Capabilities should not refer to specific technologies. It is
expected that requirements desired capability will change little over time.

Jones, et al. Expires April 21, 2005 [Page 9]

Internet-Draft OpSec Framework October 2004

Justification (why)
The justification tells why and in what context the requirement capability is
important.

Jones, et al. Expires October 20, 2004 [Page 4]

Internet-Draft OpSec Framework April 2004

For example, "Secure channels are important because they insure
confidentiality, and integrity. This is important in contexts
where management is performed in-band over networks with
potentially hostile users."

The justification is intended to give operators information needed
to determine the applicability of a requirement to capability their local
environment.

Examples (how)
Examples are intended to give examples of technology and standards
current at the time of writing that meet implement the requirement. capability.
Examples of configuration and usage may also be given.

For example, "SSH provides access to management and configuration
functions via secure channels. One way to meet provide this requirement
might capability
would be to enable SSH for in-band management and to disable all
insecure in-band management mechanisms (e.g. telnet, SNMPv1,
etc.)"

It is expected that the choice of implementations to meet provide the
requirements
capability will change over time. See [RFC3631] for a list of
some current mechanisms.

Warnings (if applicable)
The warnings list operational concerns, deviation from standards,
caveats, etc.

For example, "If SSH is chosen as the mechanism to provide secure
channels for remote management and configuration, then there are a
number of issues which must be considered including key
distribution and known vulnerabilities in various protocol
versions."

1.6

1.8 Applicability

These requirements capabilities are intended to give guidance on how best to
protect communications infrastructure. Service Providers, Network
Operators, and Equipment Suppliers are encouraged to study these
requirements,
capabilities, and prioritize the extent and manner in which they may
implement and/or deploy equipment supporting these requirements. capabilities.

Decisions of whether or not to support a specific requirement capabilities are
intended to be left with the responsible organization (e.g., Service

Jones, et al. Expires April 21, 2005 [Page 10]

Internet-Draft OpSec Framework October 2004

Provider, Network Operator, or Equipment Supplier). Due to the
continuously evolving nature of security threats to networks, and due
to significant variations in the specific security threats and
requirements in different network environments, it is not appropriate
to mandate implementation of these requirements capabilities through legislation
or regulation, nor would any mandate be consistent with their intent.

1.7

1.9 Intended Use

It is anticipated that the requirements capabilities in these documents will be

Jones, et al. Expires October 20, 2004 [Page 5]

Internet-Draft OpSec Framework April 2004
used for the following purposes:
o as a checklist when evaluating networked products,
o to create profiles of different subsets of the requirements capabilities which
describe the needs of different devices, organizations, and
operating environments,
o to assist operators in clearly communicating their security
requirements,
o as high level guidance for the creation of detailed test plans.
o as guidance for vendors to make appropriate decisions for
engineering feature roadmaps.

1.8

1.10 Definitions
NOTE: THE FOLLOWING DEFINITIONS NEED TO BE DISCUSSED AT THE WORKING
GROUP
BCP [XXX Discuss @ Working Group]
Should we work on refining the definitions of "Current" and
"Practice" ? Does "current" mean that it's widely implemented,
that at least one vendor implements, other ??? Does "Practice"
mean "requirement". See [RFC2026].
Requirement [XXX Discuss @ Working Group]
See Section 1.5 for a definition and example of the term
"Requirement" as it is used in this document.
RFC 2119 Keywords [XXX Discuss @ Working Group]
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 [RFC2119].

NOTE: THE FOLLOWING DEFINITIONS WERE COPIED DIRECTLY FROM THE OPSEC
DRAFT AND IN SUBSEQUENT DRAFTS OF THE FRAMEWORK THEY MAY MOVE TO THE
SPECIFIC DRAFT THAT DEALS WITH THE TERM DEFINED. THEY ARE LEFT HERE
NOW TO INDICATE THAT THESE ARE AREAS THAT ARE LIKELY TO NEED
DISCUSSION AND DEFINITION IN THE SUBSEQUENT EFFORTS OF THE WORKING
GROUP. The following definitions are take from RFC3871. Unless
otherwise stated, the working group documents will use these terms as
defined below.

Bogon.
A "Bogon" (plural: "bogons") is a packet with an IP source address
in an address block not yet allocated by IANA or the Regional
Internet Registries (ARIN, RIPE, APNIC...) as well as all
addresses reserved for private or special use by RFCs. See
[RFC3330] and [RFC1918].
CLI.
Several requirements capabilities refer to a Command Line Interface (CLI).
While this refers at present to a classic text oriented command
interface, it is not intended to preclude other mechanisms which
may meet provide all the requirements capabilities that reference "CLI".
Console.
Several requirements capabilities refer to a "Console". The model for this is
the classic RS232 serial port which has, for the past 30 or more
years, provided a simple, stable, reliable, well-understood and
nearly ubiquitous management interface to network devices. Again,

Jones, et al. Expires October 20, 2004 [Page 6]

Internet-Draft OpSec Framework April 2004
these requirements capabilities are intended primarily to codify the benefits

Jones, et al. Expires April 21, 2005 [Page 11]

Internet-Draft OpSec Framework October 2004

provided by that venerable interface, not to preclude other
mechanisms that meet all provide the same requirements. capabilities.
Filter.
In this document, a "filter" is defined as a group of one or more
rules where each rule specifies one or more match criteria.
In-Band management.
"In-Band management" is defined as any management done over the
same channels and interfaces used for user/customer data.
Examples would include using SSH for management via customer or
Internet facing network interfaces.
High Resolution Time.
"High resolution time" is defined in this document as "time having
a resolution greater than one second" (e.g. milliseconds).
IP.
Unless otherwise indicated, "IP" refers to IPv4.
Management.
This document uses a broad definition of the term "management".
In this document, "management" refers to any authorized
interaction with the device intended to change its operational
state or configuration. Data/Forwarding plane functions (e.g.
the transit of customer traffic) are not considered management.
Control plane functions such as routing, signaling and link
management protocols and management plane functions such as remote
access, configuration and authentication are considered to be
management.
Martian.

Per [RFC1208] "Martian: Humorous term applied to packets that turn
up unexpectedly on the wrong network because of bogus routing
entries. Also used as a name for a packet which has an altogether
bogus (non-registered or ill-formed) Internet address." For the
purposes of this document Martians are defined as "packets having
a source address that, by application of the current forwarding
tables, would not have its return traffic routed back to the
sender." "Spoofed packets" are a common source of martians.
Note that in some cases, the traffic may be asymmetric, and a
simple forwarding table check might produce false positives. See
[RFC3704]
Out-of-Band (OoB) management.
"Out-of-Band management" is defined as any management done over
channels and interfaces that are separate from those used for
user/customer data. Examples would include a serial console
interface or a network interface connected to a dedicated
management network that is not used to carry customer traffic.
Open Review.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 7] 12]

Internet-Draft OpSec Framework April October 2004

Open Review.

"Open review" refers to processes designed to generate public
discussion and review of technical solutions such as data
communications protocols and cryptographic algorithms with the
goals of improving and building confidence in the final solutions.
For the purposes of this document "open review" is defined by
[RFC2026]. All standards track documents are considered to have
been through an open review process.
It should be noted that organizations may have local requirements
that define what they view as acceptable "open review". For
example, they may be required to adhere to certain national or
international standards. Such modifications of the definition of
the term "open review", while important, are considered local
issues that should be discussed between the organization and the
vendor.
It should also be noted that section 7 of [RFC2026] permits
standards track documents to incorporate other "external standards
and specifications".
Service.
A number of requirements capabilities refer to "services". For the purposes of
this document a "service" is defined as "any process or protocol
running in the control or management planes to which non-transit
packets may be delivered". Examples might include an SSH server,
a BGP process or an NTP server. It would also include the
transport, network and link layer protocols since, for example, a
TCP packet addressed to a port on which no service is listening
will be "delivered" to the IP stack, and possibly result in an
ICMP message being sent back.
Secure Channel.
A "secure channel" is a mechanism that ensures end-to-end
integrity and confidentiality of communications. Examples include
TLS [RFC2246] and IPsec [RFC2401]. Connecting a terminal to a
console port using physically secure, shielded cable would provide
confidentiality but possibly not integrity.
Single-Homed Network.
A "single-homed network" is defined as one for which
* There is only one upstream connection
* Routing is symmetric.
See [RFC3704] for a discussion of related issues and mechanisms
for multihomed multi-homed networks.
Spoofed Packet.
A "spoofed packet" is defined as a packet that has a source
address that does not correspond to any address assigned to the
system which sent the packet. Spoofed packets are often "bogons"
or "martians".
Secure Network

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 8] 13]

Internet-Draft OpSec Framework April October 2004

Secure Network

For the purposes of these documents, a secure network is one in
which:
* The network keeps passing legitimate customer traffic
(availability).
* Traffic goes where it is supposed to go, and only where it is
supposed to go (availability, confidentiality).
* The network elements remain manageable (availability).
* Only authorized users can manage network elements
(authorization).
* There is a record of all security related events
(accountability).
* The network operator has the necessary tools to detect and
respond to illegitimate traffic.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 9] 14]

Internet-Draft OpSec Framework April October 2004

2. Documents

[Ed. This list of documents is likely to be consolidated/reduced]

The following is a list of documents to be produced by OPSEC working
group. Each document is intended to cover an area important to
secure operation of large network infrastructure.

2.1 Standards Survey (info)
Overview
This document provides an overview of other efforts in developing
standards, guidelines, best practices, or other information
intended to facilitate improvement in network security. Any
effort which is known, such as the ANSI T1.276, the NRIC V "Best
Practices", ITU-T M.3016 and X.805, the T1S1 effort on securing
signalling will be included. The intent is to provide a clear
understanding of which efforts are complementary and/or
contradictory such that any efforts of future cross-certification
of standards may be facilitated.
Security Considerations
Any
Many contradictory security requirements from varying standards
bodies would seriously impact operator or vendor understanding of
which features and functionalities are the most effective to
deploy and operate secure networks. This documented survey will
help to ensure that there is a consistent set of product
requirements to follow.

2.2 In-Band management requirements capabilities (BCP)
Overview
Although there are known security issues with in-band management,
there are many situations where in-band management makes sense, is
used, and/or is the only option. The features recommended in this
document will provide for a more secure means of using any in-band
management functionality.
Security Considerations
Although in-band management has the advantage of lower cost (no
extra interfaces or lines), it has significant security
disadvantages:
* Saturation of customer lines or interfaces can make the device
unmanageable unless out-of-band management resources have been
reserved
* Since public interfaces/channels are used, it is possible for
attackers to directly address and reach the device and to
attempt management functions.
* In-band management traffic on public interfaces may be
intercepted, however this would typically require a significant
compromise in the routing system.

Jones, et al. Expires April 21, 2005 [Page 15]

Internet-Draft OpSec Framework October 2004

* Public interfaces used for in-band management may become
unavailable due to bugs (e.g. buffer overflows being
exploited) while out-of-band interfaces (such as a serial

Jones, et al. Expires October 20, 2004 [Page 10]

Internet-Draft OpSec Framework April 2004
console device) remain available
The requirements capabilities from this document are meant to provide the means
of securing in-band management traffic.

2.3 Out-of-Band management requirements capabilities (BCP)
Overview
This document will describe requirements capabilities related to out of band
management of networked devices.
Security Considerations
Out-of-band management often provides a more secure means of
managing networked devices. To ensure that all devices have the
appropriate support, this document will set requirements list capabilities as to
what functionality is needed to effectively use out-of-band
management.

2.4 Filtering requirements capabilities (BCP)
Overview
This document will describe requirements capabilities related to stateless
filtering requirements for network elements providing transit service at OSI layers 2 link
and 3. transport layers.
Security Considerations
Filtering is an important security functionality to permit or deny
forwarding of traffic, or to specify special treatment of packets,
depending on layer 2 or layer 3 header and forwarding information.
It provides a basic means of implementing policies, such as
policies that specify which traffic is allowed and which is not,
and policies which specify special treatment such as setting CoS,
rate limiting, or packet copying. It also provides a basic tool
for responding to malicious traffic.

2.5 Event Logging Requirements Capabilities document (BCP)
Overview
[Ed. The basic questions here are "what gets logged", "how does
it get logged", "what are the security issues". There is work in
progress (syslog) for the last two that can be cited. The "what
gets logged" question needs work]
This document will describe the recommended features when logging
network device traffic and anomalies. The goal is to make it
possible to correlate logging information from varying systems and
making sure that logged information is useful and effective.
Security Considerations
Logging data provides a means for detecting malicious behavior.
The logged information can also be used as evidence in legal
prosecution cases against illegal network access and device
compromises. Ineffective logging practices due to inconsistent

Jones, et al. Expires April 21, 2005 [Page 16]

Internet-Draft OpSec Framework October 2004

functionality in many devices make it hard to get effective data.
This document will help provide consistent logging functionality
for more effective auditing. It will also point to privacy or

Jones, et al. Expires October 20, 2004 [Page 11]

Internet-Draft OpSec Framework April 2004
legal considerations when logging/monitoring user activity.

2.6 Configuration and Management Interface Requirements Capabilities (BCP)
Overview
This document lists the security requirements capabilities necessary for
interfaces which allow for configuring and managing the network
device. In most cases, this currently involves some sort of
command line interface (CLI) and configuration files. It may be
possible to meet these
requirements provide the capabilities with other mechanisms, for
instance SNMP or a script-able HTML interface that provides full
access to management and configuration functions. In the future,
there may be others (e.g. XML based configuration).
Security Considerations
The interfaces used to manage and configure network elements need
to be effectively secured to avoid a malicious user from being
able to logically gain illegal access. In the past, many security
vulnerabilities have been discovered, especially with SNMP and
HTTP access to devices. These recommendations will help the user
and vendor community mitigate any known risks in this area.

2.7 AAA requirements capabilities document (BCP)
Overview
This document will list the requirements capabilities needed for centralized
authentication, authorization and accounting functionality.
Security Considerations
Keeping track of who has access to network devices is critical to
any secure infrastructure. Mechanisms to provide authorized
access upon successful authentication and also keeping track of
what was done can provide important information in case of a
device compromise.

2.8 Documentation and Assurance requirements capabilities document (BCP)
Overview
These requirements capabilities will list information which should be
documented that will assist operators in evaluating and securely
operating a device.
Security Considerations
Devices many times have default behavior which can cause a severe
security vulnerability. Knowing which services are enabled by
default or which commands impact other default behavior is
essential knowledge that is necessary to effectively mitigate
security risks.

2.9 Miscellaneous requirements document (BCP)
Overview

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 12] 17]

Internet-Draft OpSec Framework April October 2004

2.9 Miscellaneous capabilities document (BCP)
Overview
This document will describe requirements capabilities which do not fit into any
of the other documents, and which are brief enough that they don't
justify their own document, but which are important enough that
they should be documented.

2.10 Large ISP Operational Security Requirements Capabilities Profile (info)
Overview
This document will provide a profile specifying which of the
requirements
capabilities outlined in the set of documents described above are
most applicable to large Internet Service Providers offering
transit service.

2.11 Large Enterprise Operational Security Requirements Capabilities Profile (info)
Overview
This document will provide a profile specifying which of the
requirements
capabilities outlined in the set of documents described above are
most applicable to large Enterprise networks.

2.12 OPSEC Deliberation Summary document (info)
Overview
This document will provide a summary of discussions that have
taken place within the OPsec working group. The intent is to
document ideas that were "left on the cutting room floor" in order
to provide a possible starting point for future work.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 13] 18]

Internet-Draft OpSec Framework April October 2004

3. Security Considerations

Security is the entire focus of this document.

Jones, et al. Expires October 20, 2004 [Page 14]

Internet-Draft OpSec Framework April 2004

4. References

4.1

4 Normative References

[RFC1208] Jacobsen, O. and D. Lynch, "Glossary of networking terms",
RFC 1208, March 1991.

[RFC1812] Baker, F., "Requirements for IP Version 4 Routers", RFC
1812, June 1995.

[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G. and
E. Lear, "Address Allocation for Private Internets", BCP
5, RFC 1918, February 1996.

[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2196] Fraser, B., "Site Security Handbook", RFC 2196, September
1997.

[RFC2246] Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. T. and P. Kocher, C. Allen, "The TLS Protocol Version 1.0",
RFC 2246, January 1999.

[RFC2401] Kent, S. and R. Atkinson, "Security Architecture for the
Internet Protocol", RFC 2401, November 1998.

[RFC3013] Killalea, T., "Recommended Internet Service Provider
Security Services and Procedures", BCP 46, RFC 3013,
November 2000.

[RFC3330] IANA, "Special-Use IPv4 Addresses", RFC 3330, September
2002.

[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552, July
2003.

[RFC3631] Bellovin, S. and J. S., Schiller, J. and C. Kaufman, "Security
Mechanisms for the Internet", RFC 3631, December 2003.

[RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed
Networks", BCP 84, RFC 3704, March 2004.

4.2 Non-normative References

[I-D.savola-bcp38-multihoming-update]
Baker, F. and P. Savola, "Ingress Filtering

[RFC3871] Jones, G., "Operational Security Requirements for Multihomed
Networks", draft-savola-bcp38-multihoming-update-03 (work Large
Internet Service Provider (ISP) IP Network
Infrastructure", RFC 3871, September 2004.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 15] 19]

Internet-Draft OpSec Framework April October 2004

in progress), December 2003.

[Schneier]
Schneier, B., "Applied Crytography, 2nd Ed., Publisher
John Wiley & Sons, Inc.", 1996.

Authors' Addresses

George M. Jones
The MITRE Corporation
7515 Colshire Drive, M/S WEST
McLean, Virginia 22102-7508
U.S.A.

Phone: +1 703 488 9740
EMail: gmjones@mitre.org

Ross Callon
Juniper Networks
10 Technology Park Drive
Westford, MA 01886
U.S.A.

Phone: +1 978 692 6724
EMail: rcallon@juniper.net

Merike Kaeo
Double Shot Security
520 Washington Blvd. #363
Marina Del Rey, CA 90292
U.S.A.

Phone: +1 310 866 0165
EMail: kaeo@merike.com

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 16] 20]

Internet-Draft OpSec Framework April October 2004

Appendix A. Acknowledgments

The authors gratefully acknowledge the contributions of:
o Acknowledgments to be determined.
o The MITRE Corporation for supporting development of this document.
NOTE: The author's affiliation with The MITRE Corporation is
provided for identification purposes only, and is not intended to
convey or imply MITRE's concurrence with, or support for, the
positions, opinions or viewpoints expressed by the editor.
o This listing is intended to acknowledge contributions, not to
imply that the individual or organizations approve the content of
this document.
o Apologies to those who commented on/contributed to the document
and were not listed.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 17] 21]

Internet-Draft OpSec Framework April October 2004

Intellectual Property Statement

The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.

Disclaimer of Validity

This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.

Acknowledgment

Funding for the RFC Editor function is currently provided by the
Internet Society.

Jones, et al. Expires October 20, 2004 April 21, 2005 [Page 18] 22]