[c-nsp] 3850?

Łukasz Bromirski lukasz at bromirski.net
Sat Apr 11 05:43:41 EDT 2015


> On 11 Apr 2015, at 00:26, Adam Greene <maillist at webjogger.net> wrote:
> 
> We're not actually doing Netflow of any kind yet. 

OK.

> It looks like most of our input queue drops are due to 'encapsulation failed' ... i.e. bogus traffic to non-existent hosts. So far it hasn't affected legitimate network performance, as far as we can tell.

I’d SPAN that traffic and take a look. You shouldn’t have that much
traffic resulting in encapsulation failed, unless it’s very “dirty”
access network, with a lot of botnets spewing spoofed/random traffic
all around.

> So maybe the 3750/3750G's will actually be able to support 450Mbps aggregate gracefully and we can afford to avoid upgrading for now ... that's a nice surprise.

3750/3750G are gigabit switches, and they should support up to
1Gbit/s per port. I actually read whole thread, and the first
answer You got was about tuning buffers - did you do that?

Remember, those are “Enteprise” switches, so their QoS and
buffers by default reflect access scenario with rather lazy
workstation generating traffic in peaks.

You need to turn MLS QoS on, and then tune buffers to be
able to accept traffic at high rates.

> (b) to respond to customer congestion complaints by explaining, "you are using your whole pipe to download windows updates: schedule those for off-hours!" etc.

If that’s also a problem, try to set up local cache to offload
that kind of things as close customers as you can.

-- 
"There's no sense in being precise when |               Łukasz Bromirski
 you don't know what you're talking     |      jid:lbromirski at jabber.org
 about."               John von Neumann |    http://lukasz.bromirski.net



More information about the cisco-nsp mailing list