I recently added a couple Catalyst 3850′s to my development rack as we are starting to develop them internally. I’ll do a few more detailed blog posts on the Catalyst 3850 in the near future but I just wanted to show how simple it is to perform basic QoS functions using the MQC on the 3850. Below is the configuration to limit VLAN 15 traffic received on a trunk link from a router to 512k.

class-map match-any test
  match vlan  15
policy-map test
 class test
    police cir 512000
interface GigabitEthernet1/0/5
 switchport mode trunk
 load-interval 30
 service-policy input test

Not only is it extremely simple to configure and intuitive from an IOS perspective but you actually get output from the show policy-map command.

Rack1SW1#sho policy-map interface g1/0/5

  Service-policy input: test

    Class-map: test (match-any)
      Match: vlan  15
          cir 512000 bps, bc 16000 bytes
        conformed 18935704 bytes; actions:
        exceeded 761225593 bytes; actions:
        conformed 0000 bps, exceed 0000 bps

    Class-map: class-default (match-any)
      Match: any

I can’t imagine having to use the 3750 or 3560 switch anymore after working on the 3850 much less doing QoS on them. Basically if you know the IOS then you already know how to configure the 3850.

Rack1SW1#sho ver | in Software
Cisco IOS Software, IOS-XE Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 03.02.01.SE RELEASE SOFTWARE (fc1)
About Brian Dennis, CCIE #2210:

Brian Dennis has been in the networking industry for more than 22 years, with a focus on Cisco networking for the past 16 years. Brian achieved his first CCIE in Routing & Switching in 1996, and is currently the only ten year CCIE that holds five CCIE certifications. Prior to working with INE, Brian taught and developed CCIE preparation courses for various well known training organizations. Brian not only brings his years of teaching experience to the classroom, but also years of real world enterprise and service provider experience.

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One Response to “Cisco Catalyst 3850 – QoS Quick Note”

  1. Michael Kiefer, CCIE# 34420 (R&S) says:

    It’s about time they simplified the switch QOS! Nice to know.


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