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At the edge, the last router before your server has to have a mapping that a single particular IPv6 address maps to a specific MAC address. You can't really condense this down to a single entry, because any given switchport might have multiple MAC addresses active (think of the case where you have a dumb switch attached to your router, and 20 servers attached to that dumb switch. You're looking at 20 different mac addresses, so no way to condense that down to a few entries).

Even a /64 is more then enough to blow up a router at this point. The /48 just makes it a lot more likely that that will happen.

The simplest solution here is to route the entire /48 at a specific IPv6 address. This brings you back down to a couple table entries, but requires that your customer configure things properly.




That's when you do DHCP-PD and the router (last hop before your server) sets up a route for that entire /48 to the link-local address of your server.

Or you set up a static route (as a provider this would be recommended) or let the edge do a BGP announcement of it's address space.


Why do either of these solve the problem mentioned, and why would you allocate a /48 to a single server?


Wait, when you said

"...the router (last hop before your server) sets up a route for that entire /48 to the link-local address of your server."

Was "your server" the ISP's server, or the customer's server? If the former, why are you saying "server", rather than "router"?


It's the customers server. If they need a /48 of address space, you just want to route all of it to them.




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