IETF 79 Proceedings

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Network Endpoint Assessment (nea) (WG)

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Additional information is available at tools.ietf.org/wg/nea

Chair(s): Susan Thomson Stephen Hanna Security Area Director(s): Stephen Farrell Sean Turner Security Area Advisor: Stephen Farrell

Meeting Slides

• IETF79 NEA WG Slides

No Current Internet-Drafts

Request for Comments:

• Network Endpoint Assessment (NEA): Overview and Requirements (RFC 5209) (132227 bytes)
• PA-TNC: A Posture Attribute (PA) Protocol Compatible with Trusted Network Connect (TNC) (RFC 5792) (193345 bytes)
• PB-TNC: A Posture Broker (PB) Protocol Compatible with Trusted Network Connect (TNC) (RFC 5793) (169140 bytes)

Charter (as of 2011-03-31)

Network Endpoint Assessment (NEA) architectures have been implemented
in the industry to assess the "posture" of endpoint devices for the
purposes of monitoring compliance to an organization's posture policy
and optionally restricting access until the endpoint has been updated
to satisfy the posture requirements. An endpoint that does not comply
with posture policy may be vulnerable to a number of known threats that
may exist on the network. The intent of NEA is to facilitate corrective
actions to address these known vulnerabilities before a host is exposed
to potential attack. Note that an endpoint that is deemed compliant may
still be vulnerable to threats that may exist on the network. The
network may thus continue to be exposed to such threats as well as the
range of other threats not addressed by maintaining endpoint
compliance.

Posture refers to the hardware or software configuration of an endpoint
as it pertains to an organization's security policy. Posture may
include knowledge that software installed to protect the machine (e.g.
patch management software, anti-virus software, host firewall software,
host intrusion protection software or any custom software) is enabled
and up-to-date. An endpoint supporting NEA protocols can be queried for
posture information.

An organization may make a range of policy decisions based on the
posture of an endpoint. NEA is not intended to be prescriptive in this
regard. Supported deployment scenarios will include, but are not
limited to, providing normal access regardless of compliance result
along with any recommendations for remediation ("advisory mode"), as
well as providing restricted access sufficient for remediation purposes
and any essential services until an endpoint is in compliance
("mandatory mode"). Specifying mechanisms for providing restricted
access is outside the scope of the NEA WG.

Since NEA involves many different components from different vendors,
interoperability is important. The NEA working group will
develop standard protocols at the following three layers in the
architecture:
the Posture Attribute protocol (PA), the Posture Broker protocol
(PB), and the Posture Transport protocol (PT). PA and PB will be
designed to
support a variety of PT protocols. Together, PA, PB and the mandatory to
implement PT protocols will allow interoperability between an NEA Client
from one vendor and an NEA Server from another.

Since there are already several non-standard protocols at these
layers, the NEA working group will consider these existing protocols as
candidates for the standard protocols. A requirements document will be
written and used as a basis for evaluating the candidate protocols. The
working group may decide to standardize one of the candidate protocols,
use one of them as a basis for a new or revised protocol, or decide
that a new protocol is needed.

The NEA Requirements document will include a problem statement,
definition of terms, requirements for the PA and PB protocols, and an
overall security analysis. It will also include generic requirements
for the protocol transporting PA, PB: the Posture Transport protocol
(PT).

The PA (Posture Attribute) protocol consists of posture attributes that
are carried between a particular Posture Collector in a NEA client and
a particular Posture Validator in a NEA Server. The PA protocol is
carried inside the PB protocol. A base set of standard posture
attributes will be specified that are expected to address many common
posture policies. Vendor-specific attributes will also be supported;
vendor-specific attributes will be identified by a private enterprise
number and a vendor assigned value. Vendors are strongly encouraged to
document vendor-specific attributes in an RFC. The NEA WG will
investigate the use of a standard syntax for all attributes.

The PB (Posture Broker) protocol aggregates posture attributes from one
or more Posture Collectors in an NEA client and sends them to the NEA
server for assessment by one or more Posture Validators.

The PT (Posture Transport) protocol carries the PB protocol. The
expectation
is that the PT protocol is a shim protocol that defines an
encapsulation of PB
within an existing standard transport protocol. Existing standard transport
protocols will be leveraged to the extent possible. The NEA WG may specify
more than one PT to meet the requirements of different deployment
scenarios.
The NEA WG will specify at least one mandatory to implement PT protocol.
PT protocol specifications must describe any limitations
that they impose on PB and PA (e.g. half duplex).

One commonly discussed issue with NEA systems is how to handle
compromised endpoints, whose reports of their own posture may not be
accurate. Detecting or handling such endpoints is out of scope of the
NEA WG. Work on PA will focus on attributes useful for assessing
posture of those endpoints reporting accurate information. However, the
protocols developed by the NEA WG must be designed to accommodate
emerging technologies for identifying and dealing with lying endpoints.

Note that NEA is not chartered to develop standard protocols for
remediation. NEA is intended to be used with new or existing tools that
can be used in the absence of NEA. NEA is applicable to computing
enterprise environments, where endpoints accessing the enterprise's
network are owned and/or expected to conform to the policies set forth
by the organization that owns and operates the network. All other
cases are outside the scope of the NEA charter, since we do not know
that NEA would be useful in such cases. NEA applicability and security
considerations will be described in the appropriate NEA documents.

Further work in the NEA WG will be considered via the rechartering
process after the completion of these milestones.

Goals and Milestones:

Done		At IETF 67, discuss issues with NEA Requirements I-D
Done		Submit first draft of NEA Requirements I-D
Done		At IETF 68, resolve any open issues with requirements I-D
Done		Submit revised NEA requirements I-D
Done		Discuss NEA Requirements I-D
Done		Submit revised NEA requirements I-D
Done		WGLC on NEA requirements I-D
Done		At IETF 69, resolve any remaining issues raised at Last Call
Done		Submit revised NEA requirements I-D
Done		Submit NEA Requirements I-D to the IESG for IETF Last Call as Informational RFC
Done		Submit revised NEA requirements I-D
Done		Proposals for PA and PB due
Done		Review and resolve proposals at IETF 71
Done		Post first WG version of PA and PB
Done		Post second version of PA and PB
Done		Resolve issues at IETF 72
Done		Post third version of PA and PB
Done		WGLC on PA and PB
Done		Resolve WGLC comments at IETF 73
Done		Post fourth version of PA and PB
Done		IETF LC for PA and PB
Done		IESG considers PA and PB for Proposed Standard
Sep 2009		Call for proposals for the PT protocol(s)
Oct 2009		Proposals due
Nov 2009		Review PT protocol proposals at IETF 76 Decide how to resolve differences and issues
Dec 2009		Post first WG version of PT protocol(s)
Jan 2010		Review and resolve issues
Feb 2010		Post second WG version of PT protocol(s)
Mar 2010		WG Last Call on PT protocol(s) Resolve issues from WG Last Call at IETF 77
Apr 2010		Post third WG version of PT protocol(s)
May 2010		Submit PT protocol(s) to IESG