nanog mailing list archives

Re: [ppml] too many variables


From: bmanning () vacation karoshi com
Date: Thu, 9 Aug 2007 21:04:04 +0000


On Thu, Aug 09, 2007 at 07:24:58AM -1000, Randy Bush wrote:

the fib in a heavily peered dfz router does not often converge now.  

        never?  or over some predefined period of time?

the
question is when will the router not be able to process the volume of
churn, i.e. fall behind further and further?  

        yes.  presuming the churn ratio stays the same and:

as there is non-trivial
headroom in the algorithms, 

        the BGP algorithm does not change  (BGP-5, BGP-6 etc anyone)

moore's law on the processors, etc. etc.,

        yes, yes, yes... too many variables.  fixing the processors
        to what is fielded TODAY, with existing algorithms, etc...
        if the ONE variable is to allow enough memory to hold prefixen,
        will BGP fail (a router not being able to process the volume of
        churn) at what point?

        (other variables:  number of exteranal peers, IGP updates, AS
        path length, etc... what else needs to be considered?)

your message is as operationally meaningful as dave and john telling us
they can handle 2m prefixes today.

        well, maybe.  the numbers were collected from live boxen.
        not enough data for anything you might be able to use tho.


randy


Current thread: