A new Request for Comments is now available in online RFC libraries. RFC 4576 Title: Using a Link State Advertisement (LSA) Options Bit to Prevent Looping in BGP/MPLS IP Virtual Private Networks (VPNs) Author: E. Rosen, P. Psenak, P. Pillay-Esnault Status: Standards Track Date: June 2006 Mailbox: erosen@cisco.com, ppsenak@cisco.com, ppe@cisco.com Pages: 7 Characters: 15149 Updates/Obsoletes/SeeAlso: None I-D Tag: draft-ietf-ospf-2547-dnbit-04.txt URL: http://www.rfc-editor.org/rfc/rfc4576.txt This document specifies a procedure that deals with a particular issue that may arise when a Service Provider (SP) provides "BGP/MPLS IP VPN" service to a customer and the customer uses OSPFv2 to advertise its routes to the SP. In this situation, a Customer Edge (CE) Router and a Provider Edge (PE) Router are OSPF peers, and customer routes are sent via OSPFv2 from the CE to the PE. The customer routes are converted into BGP routes, and BGP carries them across the backbone to other PE routers. The routes are then converted back to OSPF routes sent via OSPF to other CE routers. As a result of this conversion, some of the information needed to prevent loops may be lost. A procedure is needed to ensure that once a route is sent from a PE to a CE, the route will be ignored by any PE that receives it back from a CE. This document specifies the necessary procedure, using one of the options bits in the LSA (Link State Advertisements) to indicate that an LSA has already been forwarded by a PE and should be ignored by any other PEs that see it. [STANDARDS TRACK] This document is a product of the Open Shortest Path First IGP Working Group of the IETF. This is now a Proposed Standard Protocol. STANDARDS TRACK: This document specifies an Internet standards track protocol for the Internet community,and requests discussion and suggestions for improvements.Please refer to the current edition of the Internet Official Protocol Standards (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. This announcement is sent to the IETF list and the RFC-DIST list. Requests to be added to or deleted from the IETF distribution list should be sent to IETF-REQUEST@IETF.ORG. Requests to be added to or deleted from the RFC-DIST distribution list should be sent to RFC-DIST-REQUEST@RFC-EDITOR.ORG. Details on obtaining RFCs via FTP or EMAIL may be obtained by sending an EMAIL message to rfc-info@RFC-EDITOR.ORG with the message body help: ways_to_get_rfcs. For example: To: rfc-info@RFC-EDITOR.ORG Subject: getting rfcs help: ways_to_get_rfcs Requests for special distribution should be addressed to either the author of the RFC in question, or to RFC-Manager@RFC-EDITOR.ORG. Unless specifically noted otherwise on the RFC itself, all RFCs are for unlimited distribution. Submissions for Requests for Comments should be sent to RFC-EDITOR@RFC-EDITOR.ORG. Please consult RFC 2223, Instructions to RFC Authors, for further information. Joyce K. Reynolds and Sandy Ginoza USC/Information Sciences Institute ... _______________________________________________ IETF-Announce@ietf.org https://www1.ietf.org/mailman/listinfo/ietf-announce