Internet DRAFT - draft-hares-bgp-assign-afisafi

draft-hares-bgp-assign-afisafi




   Network Working Group                                                
   Internet Draft                                               S.Hares 
   Document:draft-hares-bgp-assign-afisafi-00.txt               NextHop 
                                                          Technologies, 
                                                                   Inc. 
   Expires: August 2004                                   February 2004 
    
    
                        BGP Assign AFI/SAFI numbers 
    
    
Status of this Memo 
    
      This document is an Internet-Draft and is in full conformance  
      with all provisions of Section 10 of RFC2026.  
        
      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.  
        
        
Abstract  
        
      This document describes mechanisms for assigning the AFI/SAFI 
      values for short-term use while BGP specifications are under 
      development.   
       
      These short-term AFI/SAFI values will be assigned for temporary 
      use to a particular enterprise while BGP specifications are under 
      development. After 1 year, if the BGP specification has been 
      adopted as an IDR draft, the lease will be renewed.  If the draft 
      has not be adopted, the AFI/SAFI value returns to the pool of 
      Enterprise AFI/SAFI.  This draft a means to assign these short-
      term AFI/SAFI values.  
       
       
       
 
 
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Table of Contents 
    
   1. Overview.......................................................2 
   2. Assignment Mechanism...........................................3 
   3. Protocol mechanisms............................................3 
      3.1 Support of temporary AFI/SAFI in OPEN......................3 
      3.2 Support of temporary AFI/SAFI in Dynamic Capabilities......3 
   Security Considerations...........................................3 
   References........................................................3 
   Acknowledgments...................................................4 
   Author's Addresses................................................4 
    
    
1. Overview  
    
   There is a problem with the allocation policy that is specified in 
   the current BGP spec.  Yakov Rekhter noted in email that:  
    
      "From the IANA Considerations section of the current BGP spec: 
    
         All new BGP message types, Path Attributes Type codes, Message 
         Header Error subcodes, OPEN Message Error subcodes, and UPDATE 
         Message Error subcodes MUST only be made using the Standards 
         action process defined in [RFC2434]. 
    
      From rfc2434: 
    
         Standards Action - Values are assigned only for Standards Track 
         RFCs approved by the IESG. 
      
      The problem with the Standards Action policy is that it makes   
      impossible to assign a value when a document is just an Internet 
      Draft. Yet in the routing area to advance an Internet Draft to    
      even a Proposed Standard requires more than one (interoperable)  
      implementation as a prerequisite for the advancement. Which means 
      that it is necessary to assign a value when the document is still 
      an Internet Draft, prior to the approval by the IESG. 
    
    
      So, the bottom line is that the Standards Action policy, as 
      *currently  specified in rfc2434, is unsuitable (and not just for 
      IDR, but for any WG in the Routing Area)." 
    
    
   This draft provides a operational mechanism to assign a short-term 
   allocation pool of AFI/SAFIs that may be used by an Enterprise or a 
   group of Enterprise while an Internet Draft is under consideration. 
    

 
 
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                     BGP Assign AFI/SAFI numbers        February 2004 
 
 
2. Assignment Mechanism 
 
   An enterprise may request an AFI/SAFI out of the temporary AFI/SAFI 
   space.  IANA will define a pool of 128AFIs each with 8 bits of SAFIs 
   from the top of the assignment pool with a mask of 0XFFFF FE00. 
      
   After the 1 year timeframe, if the IETF draft is accpted as an IDR 
   working group document the AFI/SAFI will be re-leased to that BGP 
   application until   If not, the AFI/SAFI will be returned to the 
   pool. 
    
   The IANA will publish the AFI/SAFI as temporary space with the 
   warning that these AFI/SAFIs will be re-assigned. 
    
3. Protocol mechanisms 
 
3.1 Support of temporary AFI/SAFI in OPEN 
    
   If an implementation utilizes an AFI/SAFI with the mask 0XFFFF FE00, 
   the OPEN may be responded to with an Error code that indicates: 
    
      XXXX value  Support of AFI/SAFI pair in temporary AFI/SAFI 
                  Number assignment not supported. 
    
3.2 Support of temporary AFI/SAFI in Dynamic Capabilities 
    
   If an implementation utilizes an AFI/SAFI with the mask 0XFFFF FE00, 
   BGP dynamic capability negotiation [DYN] may send back a CAPABILITY 
   Message error (error code 7), with a sub-code of: 
    
        4         Temporary AFI/SAFI will not accept 
        5         Temporary AFI/SAFI utilize official AFI/SAFI 
                  (where AFI/SAFI that the bgp speaker thinks is 
                   valuable is specified.) 
 
Security Considerations 
 
      Security concerns for BGP-4 are addressed in the BGP-4  
      specification, and accompanying specifications on TCP MD5 [1] and  
      IP Security[2].  No additional considerations need to be made for  
      the BGP-4 state machine description.  
    
References 
    
                     
   1 "Protection of BGP Sessions via the TCP MD5 Signature Option"  
           A. Heffernan, rfc2385.txt 


 
 
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   2 BGP-4 "Border Gateway Protocol Version 4", draft-ietf-idr-bgp4-
      23.txt 
   3 RFC2434 
    
    
    
Acknowledgments 
    
   Yakov Rekhter for his clear statement of the problem in an IDR 
   message as of 2/4/04.  Discussions with Andrew Lange and Gargi 
   Nalawade at NANOG 30.  
    
Author's Addresses 
    
   Susan Hares 
   NextHop Technologies, Incorporated 
   825 Victors Way, Suite 100 
   Ann Arbor, MI  48108-2738 
   Phone: 734.222.1600 
   Email: skh@nexthop.com 
    
     


























 
 
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