[c-nsp] bgp router

[Elmar K. Bins]

Re Gert, re Rossella

gert at greenie.muc.de (Gert Doering) wrote:

> On Wed, Jun 04, 2008 at 09:43:54AM -0700, Rossella Mariotti-Jones wrote:
> > This is good to know, thanks.
> > We're going to have at least two ISPs possibly add more in the future,
> > and a 100Mb pipe to it, which will grow to 200Mb soon. Right now we only
> > have a DS3 and a lot of the times it gets up to 40Mb. I'm assuming we'll
> > probably be pushing 80Mb easily pretty soon. This is our first BGP
> > experience, we don't want to over buy but we also don't want to get
> > stuck with a unit that's not going to be able to keep up.
> 
> My gut feeling is "go with a 7301 or 7200/NPE-G1".
>
> Why?  Because it can deliver the 200 Mbit/s bandwidth, and it's a 
> "simple" architecture - everything is software, and there is lots less
> hidden surprises than with the 6500/7600 platform.

That would depend on packet sizes. I know we're a bit extreme (most of
our packets are around 64-128 Bytes), yet...we're hitting 50% CPU
load on 7301s with like 60 Mbps of Traffic (in+out aggregated), which
amounts to around 72kpps.

If your traffic consists of considerably larger packets, you may want
to go with 7301s (G1) or 7201s (G2); if your packet sizes are small,
you need to consider hardware forwarding platforms.


> If you need lots of ethernet ports, trunk one of the GigE ports from the
> router to a L2 switch (2950T-24 or such), and use that to fan out all the
> individual ports.

Be careful if you set up an etherchannel; G1s and G2s do that in software,
too, and it takes away forwarding capacity...

Why is it, btw, that IOS doesn't use both CPU kernels there? Or did I miss
an IOS version that started doing that? (still on 12.3T here)


Yours,
	Elmi.