3850 qos configuring shaping and queue-buffer allocation

[bob brennan]

we have 4 servers at a remote site that we just started backing up from our main site. the total bandwidth available to us is 100mb form our sp. since we started doing this it has greatly affected user traffic. since there is no effective way to rate limit thru the backup application, we are taking a look at implementing qos shaping. we are using shaping instead of rate limiting because we don't want to drop traffic. the servers connect to 1gb ports on the 3850 and we would like to shape the traffic to 12.5 mb per server or 50mb total (50% of total bw). what I would like to know is how to configure the qos shaping and queue buffer allocation. I would like the queue buffers to be able to hold 1gb - 12.5 mb of data.  here is the current configuration I plan on using without the queue buffers. also it is my understanding that implementing the service policy is not supported on port-channel interfaces. these interfaces are port-channels. any help would be greatly appreciated. thanks.

Extended IP access list srvbackup-to-dp

    10 permit ip host 10.0.253.100 host 159.233.91.240

    20 permit ip host 10.0.253.101 host 159.233.91.240

Class Map match-any srvbackup-traffic (id 2)

   Match access-group name srvbackup-to-dp

Policy Map srvbackup-shaping

    Class srvbackup-traffic

      Average Rate Traffic Shaping

      cir 12500000 (bps)

[egarcial]

You can use the class map and setup a qos group. Then use the shapping command on the egress interface. There are different limitations on the 3850 switch since it use MQC QoS.

 https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_classn/configuration/xe-3se/3850/qos-classn-xe-3se-3850-book/qos-classn-grp-mtch-set.html#GUID-D9B99936-5294-4A8F-A3B3-680CD2D81D56

So you will need to do two things:

+ One is classify on ingress the traffic an set QoS groups per network segments. This will be your ingress policy

+ Two configure a egress policy. On this egress policy you will use shapping according to the QoS groups.

ingress ------->  Interface Gi a/a/a  |3850| Interface Gi b/b/b----------> egress

You can try to use this configuration. Let me know if it worked.

Ingress Ploicy
===============================================
ip access-list extended network-segment
permit ip any 192.168.0.10 0.0.0.255
!
class-map match-any network-class
match access-group name network-segment
!
policy-map QOS-marking-In
class network-class
  set qos-group 10

interface Gia/a/a
service-policy input QOS-marking-In


Egress Policy
================================================
Class-map match-all QOS-limit-Out
match qos-group 10

policy-map QOS-Limit-egress
class QOS-limit-Out
  shape average 100000000


interface TenGigabitEthernetb/b/b
service-policy output QOS-Limit-egress