Hi, I request a clarification on the following point related to RFC 6396 (Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format).
Section 4.3.4 says: "All AS numbers in the AS_PATH attribute MUST be encoded as 4-byte AS numbers." With the support 4-byte AS numbers, AS_PATH has dual encoding. It is encoded differently depending on whether the peer supports 4-byte AS numbers or not. Presumably to simplify the decoding of MRT database, MRT RFC elected to have a single format for AS_PATH. RFC 6793, which added support for 4-byte AS numbers, has such dual encoding not only for AS_PATH attribute but also for AGGREGATOR attribute. But RFC 6396 is silent on the encoding of AGGREGATOR attribute. Was that intentional or an oversight? Using a single format for AGGREGATOR attribute also will simplify decoders. In any case, it would be better if the RFC clarifies how AGGREGATOR attribute may be encoded. As a side-note, the MRT decoder BGPDUMP at http://www.ris.ripe.net/source/bgpdump/ seems to assume that AGGREGATOR attribute also uses single format of 4-byte AS numbers rather than 2-byte AS numbers (just like it does for AS_PATH attribute). As another side-note, Quagga seems to encode AGGREGATOR attribute with 4-byte AS number always for MRT. Could you please comment? Regards, Ramakrishna DTV. **************** CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. Infosys has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. Infosys reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the Infosys e-mail system. ***INFOSYS******** End of Disclaimer ********INFOSYS*** _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
