[192861] in North American Network Operators' Group
Re: 10G switch drops traffic for a split second
daemon@ATHENA.MIT.EDU (TJ Trout)
Tue Nov 29 16:28:27 2016
X-Original-To: nanog@nanog.org
In-Reply-To: <alpine.DEB.2.02.1611291845270.3558@uplift.swm.pp.se>
From: TJ Trout <tj@pcguys.us>
Date: Tue, 29 Nov 2016 13:28:22 -0800
To: Mikael Abrahamsson <swmike@swm.pp.se>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
Luke;
All l2, no l3. only 4 vlans. 2 peers trunked to a router which trunks back
to 2 devices (microwave backhauls).
Chuck;
All ports are 10g except the 2 peers are 1g and trunk back to a 10g port
for the router wan
No TCN's
Brian;
I have tried a IBM G8124 and a Ubiquiti ES-16-XG both show same exact drops
across all ports, makes me think it's a config issue. MTU, FC, something.
Andrew;
I have tried with FC disabled, but I will try that one more time.
Mikael;
Is it possible to over run the buffers of a 320gbps backplane switch with
only 1.5gbps traffic? I think the switch is rated for 140m PPS and I'm only
pushing 100k PPS
On Tue, Nov 29, 2016 at 9:47 AM, Mikael Abrahamsson <swmike@swm.pp.se>
wrote:
> On Tue, 29 Nov 2016, TJ Trout wrote:
>
> Could this be MTU? I've tried flow control, hard code duplex, stp on/off
>> etc
>>
>
> As others have pointed out, you probably have a switch with small buffers.
>
> If you also have flow control and you have something that triggers flow
> control to turn off packet forwarding, your small-buffer-switch might fill
> up all (shared) buffers on that port and now you're dropping traffic to all
> ports.
>
> So trying to find if you have something where flow control is enabled and
> is being triggered might be something worthwhile to do, and also perhaps
> just turn off flow control on all ports to make sure.
>
> --
> Mikael Abrahamsson email: swmike@swm.pp.se
>
