[170445] in North American Network Operators' Group
Switchport Counters - Take two
daemon@ATHENA.MIT.EDU (rwebb@ropeguru.com)
Thu Mar 27 12:52:07 2014
From: "rwebb@ropeguru.com" <rwebb@ropeguru.com>
To: nanog@nanog.org
Date: Thu, 27 Mar 2014 12:51:40 -0400
Reply-To: Robert Webb <rwebb@ropeguru.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Apologies to everyone for the original email with no subject. I am
having some senior email moments today.
Anyway....
So I certainly admit I am a basic networking guy and in the past have
not had to get into the nitty gritty of port statistics.
I am trying to understand some statistics off a switch port in a Nexus
4001i.
All TX and RX counters look normal except on the TX side, I am showing
1107597 input discards. Last clearing of show counters is 1d8h ago.
I have it in my mind that this particular counter is dropping packets
coming in from another port inside the switch that are to be
transmitted out to the end server.
So lets say the interface I am looking at is port 2 on the switch. So
server 1 sends a packet to port 1 on the switch. That packet then
traverses to backplane, or inside the same ASIC, to port 2 on the
switch. It is then dropped and not transmitted out to server 2.
Is the scenario I just presented correct? Not looking for the reason
in this email, just that my logical understanding is correct.
Robert
