Comment by rcxdude
11 hours ago
It's not just any memory. When it comes to core infrastructure routers those routes need to fit into specialized and expensive CAM (Content Addressable Memory) to do the lookups in hardware. And on every single one.
11 hours ago
It's not just any memory. When it comes to core infrastructure routers those routes need to fit into specialized and expensive CAM (Content Addressable Memory) to do the lookups in hardware. And on every single one.
Right but that's still not really answering his question. Sure, the constant factor is higher for router TCAM memory. Still: you can sum this post up as "in the late 1990s, tier-1 carriers filtered advertisements for all but the 'swamp' range down to /19s or smaller prefixes; now everything is the 'swamp'". Why is that?
Because IPv4 address scarcity means small blocks get sold as they are available to people in completely different parts of the Internet. With IPv6 the address space is so large that they can easily keep the blocks in one piece.