--- 1/draft-ietf-idr-aigp-12.txt 2013-12-03 10:19:04.995230511 -0800 +++ 2/draft-ietf-idr-aigp-13.txt 2013-12-03 10:19:05.027231280 -0800 @@ -1,26 +1,26 @@ Network Working Group Pradosh Mohapatra Internet Draft Cumulus Networks Intended Status: Proposed Standard -Expires: May 22, 2014 Rex Fernando +Expires: June 3, 2014 Rex Fernando Eric C. Rosen Cisco Systems, Inc. James Uttaro ATT - November 22, 2013 + December 3, 2013 The Accumulated IGP Metric Attribute for BGP - draft-ietf-idr-aigp-12.txt + draft-ietf-idr-aigp-13.txt Abstract Routing protocols that have been designed to run within a single administrative domain ("IGPs") generally do so by assigning a metric to each link, and then choosing as the installed path between two nodes the path for which the total distance (sum of the metric of each link along the path) is minimized. BGP, designed to provide routing over a large number of independent administrative domains ("autonomous systems"), does not make its path selection decisions @@ -509,21 +509,21 @@ - If the installed route to N does not have an AIGP value, set A to 0. - The "interior cost" of route T is the quantity A+m. 5. Deployment Considerations Using the AIGP attribute to achieve a desired routing policy will be more effective if each BGP speaker can use it to choose from among multiple routes. Thus is it highly recommended that the procedures of - [BESTEXT] and [CONN-REST] be used in conjunction with the AIGP + [BESTEXT] and [ADD-PATH] be used in conjunction with the AIGP Attribute. If a Route Reflector does not pass all paths to its clients, then it will tend to pass the paths for which the IGP distance from the Route Reflector itself to the next hop is smallest. This may result in a non-optimal choice by the clients. 6. IANA Considerations IANA has assigned the codepoint 26 in the "BGP Path Attributes" @@ -540,24 +540,25 @@ The spurious introduction, though error or malfeasance, of an AIGP attribute, could result in the selection of paths other than those desired. Improper configuration on both ends of an EBGP connection could result in an AIGP attribute being passed from one service provider to another. This would likely result in an unsound selection of paths. 8. Acknowledgments - The authors would like to thank Waqas Alam, Rajiv Asati, Brian - Dickson, Clarence Filsfils, Anoop Kapoor, Pratima Kini, Thomas - Mangin, Robert Raszuk, Yakov Rekhter, Eric Rosenberg, Samir Saad, - John Scudder, Shyam Sethuram, and Ilya Varlashkin for their input. + The authors would like to thank Waqas Alam, Rajiv Asati, Bruno + Decraene, Brian Dickson, Clarence Filsfils, Anoop Kapoor, Pratima + Kini, Thomas Mangin, Robert Raszuk, Yakov Rekhter, Eric Rosenberg, + Samir Saad, John Scudder, Shyam Sethuram, and Ilya Varlashkin for + their input. 9. Authors' Addresses Rex Fernando Cisco Systems, Inc. 170 Tasman Drive San Jose, CA 95134 Email: rex@cisco.com Pradosh Mohapatra @@ -575,23 +576,23 @@ Middletown, NJ 07748 Email: uttaro@att.com 10. Normative References [BGP], "A Border Gateway Protocol 4 (BGP-4)", Y. Rekhter, T. Li, S. Hares, RFC 4271, January 2006. 11. Informative References - [CONN-REST] "Fast Connectivity Restoration Using BGP Add-Path", P. - Mohapatra, R. Fernando, C. Filsfils, R. Raszuk, draft-pmohapat-idr- - fast-conn-restore-03.txt, January 2013. + [ADD-PATH] "Advertisement of Multiple Paths in BGP", D. Walton, A. + Retana, E. Chen, J. Scudder, draft-ietf-idr-add-paths-09.txt, October + 2013. [BESTEXT], "Advertisement of the Best External Route in BGP", P. Marques, R. Fernando, E. Chen, P. Mohapatra, H. Gredler, draft-ietf- idr-best-external-05.txt, January 2012. [BGP-ERROR] "Revised Error Handling for BGP UPDATE Messages", J. Scudder, E. Chen, P. Mohapatra, K. Patel, draft-ietf-idr-error- handling-04.txt, June 2013. [RFC2119] "Key words for use in RFCs to Indicate Requirement