Globally disable QoS on Cisco 3750 in production

QoS (Quality of Service) is a feature of modern networking equipment that can help ensure that important traffic such as voice and video is given priority over other less important traffic. This can be especially useful in a production environment where real-time data needs to be delivered in order to keep the production process running smoothly. However, there may be situations where it is desirable to globally disable QoS on a Cisco 3750 switch in production. In this article, we will discuss the steps necessary to do this.

The first step is to make sure that QoS is not currently enabled on the switch. This can be done by entering the show running-config command and looking for any lines that begin with “mls qos”. If any of these lines are present then QoS is currently enabled and needs to be disabled. To do this, enter the “no mls qos” command and then save the configuration by entering the “copy running-config startup-config” command. This will ensure that QoS is disabled when the switch is restarted.

The next step is to ensure that all ports on the switch are configured to use the default QoS settings. This can be done by entering the “show interface” command and looking for any lines that begin with “mls qos trust”. If any of these lines are present then the port is currently configured to use a custom QoS setting and this needs to be changed. To do this, enter the “no mls qos trust” command and then save the configuration by entering the “copy running-config startup-config” command. This will ensure that all ports are configured to use the default QoS settings when the switch is restarted.

The next step is to ensure that all traffic is being treated as best effort traffic. This can be done by entering the “show policy-map” command and looking for any lines that include the term “mark”. If any of these lines are present then traffic is currently being marked and needs to be unmarked. To do this, enter the “no policy-map class class-default” command and then save the configuration by entering the “copy running-config startup-config” command. This will ensure that all traffic is treated as best effort traffic when the switch is restarted.

Finally, the switch needs to be restarted in order for the changes to take effect. This can be done by entering the “write memory” command and then the “reload” command. This will cause the switch to restart and the changes will take effect. At this point, QoS should be globally disabled on the Cisco 3750 switch in production.

In conclusion, it is possible to globally disable QoS on a Cisco 3750 switch in production. The steps necessary to do this include making sure that QoS is not currently enabled, configuring all ports to use the default QoS settings, ensuring that all traffic is being treated as best effort traffic, and restarting the switch. Following these steps should allow an IT admin to globally disable QoS on a Cisco 3750 switch in production.