Can someone explain why loading a 1MM-route BGP table onto a network switch is a "hard problem" that requires fancy hardware to solve, rather than something that even commodity hardware today is capable of?
Presuming you do your IPv4 and IPv6 routing separately...
For IPv4, an interval-treemap from uint32-pair intervals to uint8 output ports fits into the default memory config of a PC from 1994; and each lookup into said tree resolves in nanoseconds, even on a machine of the era — esp. for tree-node pages that are hot in CPU cache.
And for IPv6, the tree could grow a lot larger, since the intervals are, per se, "uint128"-pairs... but there just aren't that many extant IPv6 routes yet, so the table is actually small in practice.
What are the constraints on the problem that I'm missing?
Presuming you do your IPv4 and IPv6 routing separately...
For IPv4, an interval-treemap from uint32-pair intervals to uint8 output ports fits into the default memory config of a PC from 1994; and each lookup into said tree resolves in nanoseconds, even on a machine of the era — esp. for tree-node pages that are hot in CPU cache.
And for IPv6, the tree could grow a lot larger, since the intervals are, per se, "uint128"-pairs... but there just aren't that many extant IPv6 routes yet, so the table is actually small in practice.
What are the constraints on the problem that I'm missing?