[c-nsp] 3560 buffering

[Jeff Bacon]

Gads. Show int count error. I can't believe I missed that. I just can't. *whacks head* 

I am (unfortunately?) running 12.2(44)SE, thus clearly shooting myself in the foot. Sigh. I've wondered about upgrading... and was planning to try QoS to prioritize the trading system traffic at least (another way around the buffering issue) - and just to turn on mls qos, so one could look at the buffering, since you need the qos commands to look and you don't have them when qos is off.

Thanks!! 

> Given a new enough IOS (at least 12.2(50)SE works) the "show interface
> counters errors" should name the specific cause. A guess might be
> "OutDiscards", which are output buffer overruns.
> 
> > Is there a way to tell the 3560 to buffer more aggressively?
> 
> There might be. If I remember correctly, the "no QoS enabled" defaults
> from 12.2(25)SEE and earlier and 12.2(46)SE and later are somewhat
> better than the version in between. We had many problems with too
> aggressive drops when moving traffic coming in a Gigabit link and out a
> FastEthernet link.
> 
> I have attached what should be a minimal configuration enabling QoS and
> adjusting the output buffer sizes. This seemed to help in our lab
> tests, making the switch behave almost like a 3550.
> 
> --
> Peter