Hi Michael, First of all, thanks for your review and comments - my apologies for not responding earlier... On Thu, Jun 6, 2019 at 11:24 PM Michael Tüxen via Datatracker <noreply@xxxxxxxx> wrote: > The document looks good from my perspective, but could make two things clearer: > * If the connectivity to one ISP break down all transport connections without specific > multihoming support will break. This includes all TCP connections. Ah, good point. If we add the following subsection to the "Section 6. Deployment Considerations" "6.1. Connections Preservation The proposed solution is not designed to preserve connection state in case of an uplink failure. When all uplinks to an ISP go down all transport connections established to/from that ISP address space will be interrupted (unless the transport protocol has specific multihoming support). That behaviour is similar to the scenario of IPv4 multihoming with NAT when an uplink failure causes all connections to be NATed to completely different public IPv4 addresses. It should be noted that in case of IPv4 NAT-based multihoming uplink recovery could cause connection interruptions as well (unless packet forwarding is integrated with existing NAT sessions tracking so the egress interface for the existing sessions is not changed). However the proposed solution has a benefit of preserving the existing sessions during/after the failed uplink restoration. Unlike the uplink failure event which causes all addresses from the affected prefix to be deprecated the recovery would just add new preferred addresses to a host without making any addresses unavailable. Therefore connections estavlished to/from those addresses do not have to be interrupted. " would it address your comment? > * The description of transport based alternatives in section 7.3 is pretty generic. > However, this might be acceptable since the main argument that it is right now > not an alternative due to limited deployment, is valid. I see what you mean but I'm not sure how to improve it...If you have any suggestions it would be highly appreciated! Thanks! -- SY, Jen Linkova aka Furry
