Subject: [secdir] Secdir review of draft-ietf-pce-p2mp-app-01

From: Brian Weis <[email-masked]>
Date: Mon, 15 Jun 2009 11:59:03 -0700

I have reviewed this document as part of the security directorate's  
ongoing effort to review all IETF documents being processed by the  
IESG. These comments were written primarily for the benefit of the  
security area directors. Document editors and WG chairs should treat  
these comments just like any other last call comments.

This Informational document describes how the Path Computation Element  
(PCE)-based architecture defined in RFC 4655 can support point-to- 
multipoint label switched paths. A PCE is a device that computes the  
path of Traffic Engineered Label Switched Paths (TE LSPs) within  
Multiprotocol Label Switching  (MPLS) and Generalized MPLS (GMPLS)  
networks. A PCE-based architecture is generally used to offload path  
computation processing from Label Switching Routers (LSRs).

This document does not substantially change the architecture described  
in RFC 4655. The Security Considerations section states that this  
document does not raise any additional security issues beyond those  
that generally apply to the PCE architecture, and I believe that is  
generally true. However, I do have one minor suggestion for the authors:

The "Note" in the Security Considerations section points out that P2MP  
computation is CPU-intensive, and posits that an attacker injecting  
spurious P2MP path computation requests may be more successful than if  
the attacker injected P2P computation requests. Since you brought up  
the attack, it would be worth noting that the use of a message  
integrity mechanism by a PCE protocol should be used to mitigate  
attacks from devices that are not authorized to send requests to the  
PCE device. I hesitate to be more specific because the document does  
not describe a particular PCE protocol.

Brian

-- 
Brian Weis
Router/Switch Security Group, ARTG, Cisco Systems
Telephone: +1 408 526 4796
Email: [email-masked]