Hi Yubao, Since you are referring to the A-D per EVI route signaling the F bit, I assume you talk about EVPN VPWS, however you mention MAC-VRF, so that’s confusing. The case you are describing – propagation of the L2-attributes extended community when readvertising the A-D per EVI or IMET route – is for sure out of the scope of rfc7432bis. Your case 1 sounds like an inter-domain model B case, which is covered by draft-rabadan-bess-evpn-inter-domain-opt-b<https://datatracker.ietf.org/doc/draft-rabadan-bess-evpn-inter-domain-opt-b/>. In this case, the Border Router just preserves the FAT label. Your case 2 sounds like a service gateway model (RFC9014 for multi-point L2 and draft-sr-bess-evpn-vpws-gateway<https://datatracker.ietf.org/doc/draft-sr-bess-evpn-vpws-gateway/> for EVPN VPWS). In this case, the gateway may change the F flag depending on its capabilities. Please have a look and let us know if you have comments. Thanks. Jorge From: wang.yub...@zte.com.cn <wang.yub...@zte.com.cn> Date: Tuesday, April 25, 2023 at 8:33 AM To: draft-ietf-bess-rfc7432...@ietf.org <draft-ietf-bess-rfc7432...@ietf.org> Cc: bess@ietf.org <bess@ietf.org> Subject: Discussion about F (Flow label) bit of draft-ietf-bess-rfc7432bis section 7.11
CAUTION: This is an external email. Please be very careful when clicking links or opening attachments. See the URL nok.it/ext for additional information. Hi all, The F bit is defined in EVPN L2-Attr extended community of draft-ietf-bess-rfc7432bis-07. When the RT-1 per EVI route including that L2-attr pass through a node which does not recognize a L2-attr EC, there will be two cases: Case1: that node change the MPLS label of that RT-1 per EVI to a label whose label operation is a swap. Case2: that node change the MPLS label of that RT-1 per EVI to a label whose label operation is a pop, and that second label identifies a local MAC-VRF. In either of these two cases, that node may propagate that L2-attr to other PEs (i.e. PE3), but in case 2 it will cause those PEs to send a flow label to it, while it cannot decapsulate that flow label thus packet drop may happen. Is there any solution to make those two cases distinguish from each other (from the viewpoint of the target receiving PE PE3) ? Thanks, Yubao
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