On Thu, 11 Jun 2020 at 21:04, David Sinn <dsinn@dsinn.com> wrote:

You've made my point for me. If you are building the core of your network out of MX's, to turn a phrase, in a past life "I fully support my competitors to do so". Large numbers of small boxes, as they have already shown in the data-center, have major cost, control and operational advantages over a small number of large ones. They also expose the inherent problems of label-switching and where IP has it's merits.

Except this implementation does not exist, but we can argue that is missing feature. We can argue we should be able to tell the lookup engine this CIDR is on-chip and it's host routes only. This is certainly doable, and would make IP tunnels like MPLS tunnels for lookup cost, just larger lookup key, which is not significant cost. But even if we had this (we don't, we have for MPLS) IP would be still inferior, it is more tunneling overhead, i.e. I need more overspeed. Technically MPLS is just better tunneling header. I can understand sentimental arguments for IPv4 and market seems to appreciate those arguments particularly well. -- ++ytti