Cisco Router best for full BGP on a sub 5K bidget 7500 7200 or other vendor ?

Michel Py michel at arneill-py.sacramento.ca.us
Tue Apr 27 02:16:51 UTC 2004


> David Barak wrote:
> the m7i is a lot of power for not so much money,

If you know of one for sale for 5K, please let me know.


>> Rodney Dunn wrote:
>> That's the most common deployment mistake I see made
>> with the 75xx nowadays. People want to move to dCEF to
>> get added feature capability or either run a new feature
>> that requires dCEF and they don't consider the extra
>> load on the VIP CPU's that is required.

> jlewis at lewis.org wrote:
> Does dCEF use much more CPU on the VIPs or just memory
> (to store the fowarwarding table on the VIP)?

Oh yes. And there are plenty of ways to mess it up, too. I never dared
running things such as QoS policy propagation via BGP plus dCAR/dwRED on
a 7500. Maybe on a VIP6, any takers? On a VIP2-50/128 as Alexander
mentioned, fugged about any extra features.


> My experience has been that a 7500 with RSP4's and VIP2-50's
> (with dCEF) will handle much more packet forwarding than a
> 7206VXR NPE300...

This is true but only if you're not fancy. VIP2-50 is a 200Mhz R5000,
that's slightly better than a 3640, not fast by any means. That's what
you find in a PDA these days. Just handling traffic for two FE PAs will
get it pretty busy already.


> but with full BGP routes, you need at least 64mb (preferably
> 128mb) on the VIPs or you can't use dCEF. Not using dCEF
> largely defeats the purpose of using a 7500, doesn't it?

Indeed.

> You'd get a 7507 (only if it were a choice between that
> or a 7505?), but then at the end of your message, you say
> you wouldn't buy any 7500?

Only if it were a choice between that and a 7505.


> A basic 7507 (dual PS, dual RSP4, couple of VIPs and PAs)
> is so cheap today, if he's strapped for cash, that's what
> I'd go for.  I'm guessing you can still get at least several
> years out of such a box, and by the time you've outgrown it
> or cisco stops making IOS for it (they still make IOS for
> AS5200's!), hopefully you'll have the cashflow to upgrade.

That summarizes is well, it's a pay me now or pay me later thing. The
7206 might be a little pricier but it will last longer, and that's one
thing to take into account when capexing hardware. The bottom line is
that as of today and given 400Mbps of traffic it does cost big buck$ to
upgrade the 7500 to RSP16 and VIP6 to be able to run everything, and
that would not be a wise investment I think.

Michel.





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