too many routes

Joseph T. Klein jtk at
Wed Sep 10 11:39:31 UTC 1997

Having hopelessly screwed up my facts ... I was trying to make a point here.
So the router was worse than I thought. Retaing policies that exclude
new players because of AGS+'s inability to handle large routing flaps
just does not cut it.

Sprint imposed this at a time when 7000s with 64M of memory where available.
Will /19 remain policy when the majors are running with Cisco 12000 and GRFs?

The CPU issue has more to do with changes in the routing table rather than
the size. Aggrigation is good because if properly implemented it reduces
router flaps. If aggregation is the goal then mechanisms should be developed
for exchanging CIDR blocks so the address space can be re-packed.

The /19 policy is archaic. It creates an obstacles and only partly resolves
the problem. Fixing holes in CIDR blocks, exchanging fragmented blocks for contiguous
blocks, and cleaning up "The Swamp" can do more for the stability and size of
the routing table.

BTW - If you use a route server to do the dampening and calculation of peer
routes you can even make a wimpy CPUed 7000 handle backbone traffic.

--- On Wed, 10 Sep 1997 10:03:07 -0500 (CDT)  Jason Vanick <jvanick at> wrote:

> > On Wed, 10 Sep 1997, Joseph T. Klein wrote:
> > 
> > > The routes issue historically comes down to the fact that Sprint did not
> > > want to convert from Cisco 4000 to Ciscos that had larger memory capacity.
> > > Memory is cheap these days ... the big boys just don't wish to have a
> > > free market.
> > 
> > I do not think sprint had 4000s in their backbone, they had AGS+ routers.
> > The problem is not the lack of memory, but that the CPU can not process
> > all the date in the memory when it needs to. The cisco 7500 have that
> > same prob, sure you can put 256 megs of RAM in them, but can the CPU
> > recalculate the next hop if most of that date in that RAM changes?
> > The new RSP4 card may have solved that, we may be at a point now where the
> > router has enough processor to be able to process all the data it has
> > stored in memory and do it quickly. 
> AGS+'s only could handle 16meg, the cpu in a AGS+ is the same as in a 7000
> series, (motorola 68040)  As of a year ago, I believe I heard that sprint 
> still had AGS+'s in their backbone and were upgrading them to 7000 series
> equipment.
> -- Jason
> Jason Vanick ------------------------------------------ jvanick at
> Network Operations Manager                                   V: 312-245-9015
> MegsInet, Inc.        225 West Ohio St. Suite #400         Chicago, Il 60610 

---------------End of Original Message-----------------

From: Joseph T. Klein, Titania Corporation
mailto:jtk at                     Sent: 11:39:32 CST/CDT 09/10/97

If the Internet stumbles, it will not be because we lack for technology,
vision, or motivation. It will be because we cannot set a direction
and march collectively into the future.

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