[c-nsp] 6500/7600 TCAM Usage

Tom Hill tom at ninjabadger.net
Tue Jun 7 16:22:23 EDT 2016

On 07/06/16 18:01, Mack McBride wrote:
> I don't think we are going to get there.
> Current growth is about 1K prefixes per week for IPv4 and has been for 2 years.
> So about 25 years to hit 2 million.
> IPv6 will max out somewhere around 3 or 4x ASN count.
> Active ASN count is still less than 100K.
> Probably also around 20 years to reach 1 million.

You presume that the number of networks is not going to speed up - I
sincerely doubt it'll be linear.

When these things become usable commodity - 32-bit ASNs and IPv6 PI
space - the automation available now can and will make mincemeat of the
current scales that we live in.

> Not saying never but the 9K will likely be in the same
> position the 6500 is by then.

Finger's crossed, but it never hurts to have headroom for the
unforeseen, i.e. DFZ in a VRF.

Note that the FIB scale increase from Trident to Typhoon was ~3x, and
Typhoon to Tomahawk is purported to be 2.5x... If Cisco is slowing down,
it's only slight, but they are /definitely/ not scaling Cat6k in the
same manner.

MPC3E-NG from Juniper has a fairly big increase in route space over its
predecessor, too. Neither company is stupid - and they pay close
attention to what each other is doing.

> I also expect table pruning and compression to be a
> Bigger part of the routing piece by then.
> Maybe an extension to BGP to request specific
> Deaggregates or LISP or some other routing

You honestly think ISPs that deaggregate on purpose are going to send
you aggregates if you ask via BGP? If only we knew that sooner! ;)

I have my tongue firmly in my cheek, and neither of us know the future,
but I'm quite happy that Cisco is still scaling the FIB far out into the


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