1 / 6

Revised Error Handling for BGP Updates from External Neighbors

Revised Error Handling for BGP Updates from External Neighbors. d raft-chen-ebgp-error-handling-00.txt. Enke Chen, Pradosh Mohapatra , Keyur Patel . IETF 79, November 2010, Beijing, China. Problem.

giona
Download Presentation

Revised Error Handling for BGP Updates from External Neighbors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Revised Error Handling for BGP Updates from External Neighbors draft-chen-ebgp-error-handling-00.txt • Enke Chen, PradoshMohapatra, Keyur Patel • IETF 79, November 2010, Beijing, China

  2. Problem • RFC4271 specifies that a malformed attribute resets the session • Relaxed for optional transitive attributes • There are other cases not covered such as • AS-PATH • Length of an optional transitive attribute • Session rest is disruptive • No distinction between good / bad prefixes • Multiple networks / ASes

  3. Goals • Minimize the scope of networks being impacted • Limit the impact to only the routes involved • Maintain the protocol correctness

  4. Proposal • Partially revise error handling for updates from EBGP • Do not reset an EBGP session if all possible • Treat as withdraw • As long as the prefixes can be parsed • Safe, like applying a filter • Debugging facility must be provided • About session integrity • NLRI field must be parsed completely • Validation of the BGP message header (synchronization header, message length and type)

  5. Parsing of the NLRI Fields • It is fundamental to the proposed approach • Format the prefixes in the very front of the message • MP-REACH / MP-UNREACH as the first attribute • Use MP-REACH / MP-UNREACH for IPv4 Unicast

  6. What about IBGP • In general “treat-as-withdraw” is unsafe for IBGP • Error handling (i.e., session reset) remains unchanged • Once prefixes are identified, apply filters at the ingress • Not pursuing automation of the procedures in protocol • Issues from EBGP typically dominate • - Require significant changes to the protocol

More Related