Using /126 for IPv6 router links

Owen DeLong owen at delong.com
Tue Jan 26 12:55:50 CST 2010


On Jan 26, 2010, at 9:22 AM, Grzegorz Janoszka wrote:

> On 26-1-2010 1:33, Owen DeLong wrote:
>>> - 	"Waste" of addresses
>>> - 	Peer address needs to be known, impossible to guess with 2^64 addresses
>> Most of us use ::1 for the assigning side and ::2 for the non-assigning side of
>> the connection.  On multipoints, such as exchanges, the popular alternative is
>> to use either the BCD of the ASN or the hex of the ASN for your first connection
>> and something like ::1:AS:N for subsequent connections.
> 
> If you have shared racks with different customers within, you can use 16 or 32 bits out of 64 as customer ID, allowing the customer to use the rest, so in fact giving him trillions (possible) IP's for one server.
> It can be use with autoconfiguration which always has FF:FE in the middle - you just use some other bits here for your customer assignments. Thus you identify a customer just by looking at the IP address.
> 
Even with shared racks, I'd never implement shared network segments between customers.

That's just asking for terrible problems.

It can't be used with autoconfiguration because the other 48 bits in the autoconf address
are the customer's MAC address, and won't be the customer ID.

Owen

> -- 
> Grzegorz Janoszka





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