[AusNOG] Cisco 6500 with Sup 720 3BXL - Good routing platform ??

[Lincoln Dale]

On 20/09/2010, at 3:33 PM, Dobbins, Roland wrote:

> Actually, this is what I was referring to, and it's very much a current issue, as it's tied into the EARL7 design:
> <http://www.cisco.com/en/US/products/hw/switches/ps708/products_white_paper09186a00800c9470.shtml#wp43500>

exhausting the LOUs is your issue?

its sort of as i've stated a few times now - knowledge of how the underlying hardware works enables you to make more informed decisions as far as what you ask it to do and how you ask it to do it.
like all things, there are often "more optimal" and "less optimal" ways of expressing things.

all vendors' boxes and indeed all platforms from cisco will have a variety of corner case behavior when you get into multi-thousand line ACLs matching on L3/L4 operations.
i can show you plenty of large internet sites using it just fine, but as you already know, improving CL-TCAM behaviour was something we worked hard on with EARL8.

i'd argue that the more common case is that most folks don't have multi-thousand-line ACLs, but i suspect we'll then get into a discussion about one of your other favourite topics - i.e. whether placing firewalls in front of hosts is a good or bad idea. :)

On 20/09/2010, at 4:11 PM, McDonald Richards wrote:

> I'm going to go out on a limb here and hate on the 6500/7600 and it's edge
> functionality as well. The CBWFQ QOS was completely non-existant back when I
> was using the things and they were only ever really good for infrastructure
> roles (between other devices inside your administrative domain).
> 
> Things may have changed in the more modern line cards and modules like the
> ES20s etc, but based on the pricing the original poster was talking about,
> it sounds like this is an ebay purchase and not something new from Cisco as
> those cards go for a whole lot more.

there's always been class-based QoS w/ WRED.  but i suspect what you're referring to is hierarchical policers/shapers.
there is significant power and die budget in silicon to do it, not to mention the high speed RAM itself.

from a platform perspective - again - its all about tradeoffs and what can be done at what cost, speed and density.  


cheers,

lincoln.