Using /126 for IPv6 router links

Grzegorz Janoszka Grzegorz at
Tue Jan 26 17:22:25 UTC 2010

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.

Grzegorz Janoszka

More information about the NANOG mailing list