Hi Eric, |I believe that this is A Good Thing because we have repeatedly |confronted huge network deployments that could not easily be supported |by two tiered (for IGP) network design hierarchies. To use |your wording, |we in Boeing have known since circa 1993 that IP is "flawed" in that |manner because we repeatedly have broken IP products and routing by our |vast size. Consequently, we eventually invented multi-tiered solutions |for such large deployments (e.g., when I last dealt with Boeing's |Corporate Enterprise network it was a 3-tiered hierarchical IGP |infrastructure). I can well imagine that similar scaling problems also |exist for EGP, though I have not worked in that domain myself.
I think that this says more about our IGP's than anything about IP. PNNI, for example, allows more layers of hierarchy. Similarly, hacking IS-IS to provide more hierarchy is also relatively trivial. None of this requires a level of virtualization. |I do not resonate with your desire that the host should have insight |into network topology. Perhaps this is because my first protocols were |BSC and SNA. I am very familiar with the weaknesses of those systems |including the operational kludges we had to endure to get them to scale |into large deployments (e.g., source routing -- ouch!!). The reason I |became excited about IP almost two decades ago was because IP freed the |host from having to know anything about the network. In my way of |thinking, this is a fundamental source of the power and attractiveness |of IP. Specifically, I do not want the host to know about the network |design because, whenever such knowledge is required, it ultimately |creates a configuration nightmare for the large end user. Agreed, but in removing the capability from the host, you also lose flexibility and generality. The strength of IP is that knowledge in the host is not _required_, but is allowed. We're doing away with that capability. Tony _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
