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Versions: 00 01                                                         
OPSEC Working Group                                             G. Jones
Internet-Draft                                     The MITRE Corporation
Expires: April 21, 2005                                        R. Callon
                                                        Juniper Networks
                                                                 M. Kaeo
                                                    Double Shot Security
                                                        October 21, 2004

     Framework for Operational Security Capabilities for IP Network

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, each
   author represents that any applicable patent or other IPR claims of
   which he or she is aware have been or will be disclosed, and any of
   which 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 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

   The list of Internet-Draft Shadow Directories can be accessed at

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

Copyright Notice

   Copyright (C) The Internet Society (2004).


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

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   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.  The intent is to provide
   clear, concise documentation of 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 a list of capabilities appropriate for large Internet Service
   Provider (ISP) and Enterprise Networks.  This work is intended to
   refine [RFC3871].

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.1   Goals  . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.2   Motivation . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.3   Threat Model . . . . . . . . . . . . . . . . . . . . . . .  4
       1.3.1   Threats Addressed, Threats Not Addressed . . . . . . .  4
       1.3.2   Active, Passive and Combined Attacks . . . . . . . . .  5
       1.3.3   Categories of Threats  . . . . . . . . . . . . . . . .  5
       1.3.4   Threat Sources . . . . . . . . . . . . . . . . . . . .  6
     1.4   Attacks  . . . . . . . . . . . . . . . . . . . . . . . . .  6
       1.4.1   Passive attacks  . . . . . . . . . . . . . . . . . . .  6
       1.4.2   Eavesdropping/Sniffing . . . . . . . . . . . . . . . .  6
       1.4.3   Off-line Cryptographic Attacks . . . . . . . . . . . .  7
       1.4.4   Active Attacks . . . . . . . . . . . . . . . . . . . .  7
       1.4.5   Replay Attacks . . . . . . . . . . . . . . . . . . . .  7
       1.4.6   Message Insertion  . . . . . . . . . . . . . . . . . .  7
       1.4.7   Message Modification . . . . . . . . . . . . . . . . .  8
       1.4.8   Message Deletion . . . . . . . . . . . . . . . . . . .  8
       1.4.9   Man-In-The-Middle  . . . . . . . . . . . . . . . . . .  8
     1.5   Scope  . . . . . . . . . . . . . . . . . . . . . . . . . .  8
     1.6   Intended Audience  . . . . . . . . . . . . . . . . . . . .  9
     1.7   Format and Definition of Capabilities  . . . . . . . . . .  9
     1.8   Applicability  . . . . . . . . . . . . . . . . . . . . . . 10
     1.9   Intended Use . . . . . . . . . . . . . . . . . . . . . . . 11
     1.10  Definitions  . . . . . . . . . . . . . . . . . . . . . . . 11
   2.  Documents  . . . . . . . . . . . . . . . . . . . . . . . . . . 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
     2.7   AAA capabilities document (BCP)  . . . . . . . . . . . . . 17
     2.8   Documentation and Assurance capabilities document (BCP)  . 17
     2.9   Miscellaneous capabilities document (BCP)  . . . . . . . . 18

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     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

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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

   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

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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

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

   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.

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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

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   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

1.4.4  Active Attacks

   Active attacks are ones where the 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
   as a 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 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 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 a passive and an active attack.
   In this type of attack, the attacker records some number of messages
   off of the wire and then plays them back to the original recipient.
   Note that the attacker does not need to be able to understand the
   messages.  He merely needs to capture and re-transmit them.

1.4.6  Message Insertion

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

   Message insertion attacks can be used to exploit known

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   vulnerabilities in protocol software.  Routers and switches implement
   protocols which 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 be able to exploit known

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 contents of the
   message may be modified and/or the intended recipient.  [need example
   specific to network 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 network operations where
   this is harmful]

1.4.9  Man-In-The-Middle

   A Man-In-The-Middle attack combines the above techniques in a special
   form: The attacker subverts the communication stream in order to pose
   as the sender to receiver and the receiver to the sender.  This
   differs fundamentally from the above forms of attack because it
   attacks the identity of the communicating parties, rather than the
   data stream itself.  Consequently, many techniques which provide
   integrity of the communications stream are 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 his own
   MAC address to gain access to a network.  The attacker can then do
   further damage by sending forged messages.  Imagine if the victim^Ôs
   IP address was that of a tftp server.  The attacker could potentially
   download invalid system images or configuration files to a network
   device and subsequently compromise that network device.

   [Ed.  - Need to review existing capabilities.  Do the threats and
   attack types listed above cover them all ?  Are there capabilities
   that imply threats and attack classes not listed above]

1.5  Scope

   The working group will produce a list of capabilities appropriate

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   o  Internet Service Provider (ISP) Networks
   o  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.

   These limitations have been made to keep the amount of work and size
   of documents manageable.  While the capabilities listed here may
   apply to systems outside the scope, no capabilities have been added
   to account for their unique needs.

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

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.

1.7  Format and Definition of Capabilities

   A separate document will be created for specific categories of
   capabilities.  Each individual capability will have the following

   Capability (what)
      The 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."

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

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

      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 capability their local

   Examples (how)
      Examples are intended to give examples of technology and standards
      current at the time of writing that implement the 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 provide this capability
      would be to enable SSH for in-band management and to disable all
      insecure in-band management mechanisms (e.g.  telnet, SNMPv1,

      It is expected that the choice of implementations to provide the
      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

1.8  Applicability

   These 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
   capabilities, and prioritize the extent and manner in which they may
   implement and/or deploy equipment supporting these capabilities.

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

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   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 capabilities through legislation
   or regulation, nor would any mandate be consistent with their intent.

1.9  Intended Use

   It is anticipated that the capabilities in these documents will be
   used for the following purposes:
   o  as a checklist when evaluating networked products,
   o  to create profiles of different subsets of the capabilities which
      describe the needs of different devices, organizations, and
      operating environments,
   o  to assist operators in clearly communicating their security
   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.

1.10  Definitions
   RFC 2119 Keywords
      The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
      in this document are to be interpreted as described in  [RFC2119].

   NOTE: The following definitions are take from RFC3871.  Unless
   otherwise stated, the working group documents will use these terms as
   defined below.

      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].
      Several 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 provide all the capabilities that reference "CLI".
      Several 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,
      these capabilities are intended primarily to codify the benefits

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      provided by that venerable interface, not to preclude other
      mechanisms that provide the same capabilities.
      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).
      Unless otherwise indicated, "IP" refers to IPv4.
      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

      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
   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.

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      "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
      It should also be noted that section 7 of [RFC2026] permits
      standards track documents to incorporate other "external standards
      and specifications".
      A number of 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 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

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      For the purposes of these documents, a secure network is one in
      *  The network keeps passing legitimate customer traffic
      *  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
      *  There is a record of all security related events
      *  The network operator has the necessary tools to detect and
         respond to illegitimate traffic.

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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)
      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
      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 capabilities (BCP)
      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
      *  Saturation of customer lines or interfaces can make the device
         unmanageable unless out-of-band management resources have been
      *  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.

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      *  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
         console device) remain available
      The capabilities from this document are meant to provide the means
      of securing in-band management traffic.

2.3  Out-of-Band management capabilities (BCP)
      This document will describe 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 list capabilities as to
      what functionality is needed to effectively use out-of-band

2.4  Filtering capabilities (BCP)
      This document will describe capabilities related to stateless
      filtering for network elements providing transit service at link
      and 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 Capabilities document (BCP)
      [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

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      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
      legal considerations when logging/monitoring user activity.

2.6  Configuration and Management Interface Capabilities (BCP)
      This document lists the security 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 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 capabilities document (BCP)
      This document will list the 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 capabilities document (BCP)
      These 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.

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2.9  Miscellaneous capabilities document (BCP)
      This document will describe 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 Capabilities Profile (info)
      This document will provide a profile specifying which of the
      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 Capabilities Profile (info)
      This document will provide a profile specifying which of the
      capabilities outlined in the set of documents described above are
      most applicable to large Enterprise networks.

2.12  OPSEC Deliberation Summary document (info)
      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.

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3.  Security Considerations

   Security is the entire focus of this document.

4  Normative References

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

   [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

   [RFC2246]  Dierks, T. and 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

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

   [RFC3631]  Bellovin, 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.

   [RFC3871]  Jones, G., "Operational Security Requirements for Large
              Internet Service Provider (ISP) IP Network
              Infrastructure", RFC 3871, September 2004.

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Authors' Addresses

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

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

   Ross Callon
   Juniper Networks
   10 Technology Park Drive
   Westford, MA  01886

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

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

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

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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.

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