Packet loss during a config commit

[SYS7EM-Daniel]

We have on the schedule to factory default the switch and configure it from scratch this weekend, but I wanted to give an update to the forum today. On the same switch a customer was maxing out their download speeds on a port with QoS enabled to set them at a 10Mbps x 10Mbps package. Once they maxed out the download speeds on their switch port all customers and backhauls connected to the switch saw latency shoot up to around ~380+ ms.

Is this normal behavior?

[sirhc]

My image didn't display in my original post so here's a dropbox link for reference to show my findings.

To upload an image use the "Upload attachment" link under the BLUE submit button

Please post up screen grabs of all your config tabs.

[SYS7EM-Daniel]

Please see the attached screen shots of our configuration.

The customer that was maxing out the connection on port 20.

QoS tab

STP tab

LAG tab

Ports tab

Status tab

[sirhc]

Well it would be nice to see the port descriptions to give us an idea of what each port is doing.

Another words which port or ports feed the switch and which ports go to what

[sirhc]

So you are not using QOS per say, just port speed limits?

Once again would be nice to know what each port goes to.

[SYS7EM-Daniel]

I have attached a screenshot with descriptions on the status tab. Our customer names would not be much help so I labeled each port as what is on that switch port.

[sirhc]

Do you have a VLANs defined?

[sirhc]

I think your problem here is Flow Control.

On any port you are defining bandwidth control disable Flow Control on that port.

My guess is that if you look at the port stats on port 1 (the uplink port) you will see a TON of Tx Pause Frames.

WHat is happening here is a shit ton of packets come into the switch destined to the customer port with a speed limit and the switch tries to buffer up the packets as you are limiting the speed and it fill the switch buffers forcing the switch to send Tx Pause Frames out port 1 to slow them down which would affect everyone on that switch.

In this case you are best to disable Flow Control on any customer port where you are limiting the speed so the switch will simply drop the packets.

[SYS7EM-Daniel]

We do have VLANs defined. We are using one management VLAN and two customer access VLANs.

I do see lots of TX pause frames on the trunk port. I have disabled flow control on ports that we are traffic shaping and I'm monitoring the switch and the attached backhauls. I'll let you know what I see.