Re: A new spin on multihoming: multihoming classes.

[Ramakrishna Gummadi <ramki@cs.berkeley.edu>]

>   I too would like to know about this 8K DFZ.
>   I can see that there are BGP convergence reasons why one might want to
> attempt to keep the size small, but this number scares me.

I may be wrong, but isn't this number from rfc2374? To quote from section
4.0:

   The size of the Top-Level Aggregation Identifier is 13 bits.  This
   allows for 8,192 TLA ID's.  This size was chosen to insure that the
   default-free routing table in top level routers in the Internet is
   kept within the limits, with a reasonable margin, of the current
   routing technology.  The margin is important because default-free
   routers will also carry a significant number of longer (i.e., more-
   specific) prefixes for optimizing paths internal to a TLA and between
   TLAs.

-ramki