cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
571
Views
0
Helpful
2
Replies

Question on QOS Configuration

kmcdonald1973
Level 1
Level 1

I am classifying traffic using NBAR and Access-lists, setting DSCP values, and then useing bandwidth percentages to reserve bandwidth for protected classes in times of high utilization.

I currently have this setup on my outside interface (connecting to PE) and have the service policy set on output (egress).

I have found that large data transfers of default-class traffic is still able to overwhelm the link and the resereved bandwidth percentages to not seem to be able to protect the data in those classes.

Question 1 - Is it common configuration to classify, mark, and set queing policies on the same interface? Or should I be classifying and marking on the ingress of the LAN interface and then apply the queing on the outside interafce egress?

Here is my current config. As you can see, I am classifying the traffic ussing access lists and NBAR, and then I am using the policy map on my outside (PE connnected) interface egress. For brevity, I have not included the contents of the access-lists. Does anyone see any issues with this config?

class-map match-all AF41

match access-group name Management

class-map match-all AF21

match access-group name Priority-Apps

class-map match-all AF31

match access-group name Critical-Apps

match protocol citrix

match protocol kerberos

match protocol ldap

policy-map SETDSCP-KABI-NA

class AF41

  bandwidth percent 20

  random-detect dscp-based

  set ip dscp af41

class AF31

  bandwidth percent 25

  random-detect dscp-based

  set ip dscp af31

class AF21

  bandwidth percent 25

  random-detect dscp-based

  set ip dscp af21

  class class-default

  set ip dscp default

  fair-queue

interface Multilink1

service-policy output SETDSCP-KABI-NA

Thanks in advance for your replies..

2 Replies 2

Jeff Van Houten
Level 5
Level 5

I think you're going to need to provide the acls and a sh policy-map command. Do you have nbar protocol discovery on the multilink interface?

Sent from Cisco Technical Support iPad App

Joseph W. Doherty
Hall of Fame
Hall of Fame

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Question 1 - Is it common configuration to classify, mark, and set queing policies on the same interface? Or should I be classifying and marking on the ingress of the LAN interface and then apply the queing on the outside interafce egress?

I don't know how common one technique is vs. the other, as QoS is still a bit uncommon, but if possible, I personally prefer doing everything in the egress policy.

Does anyone see any issues with this config?

I normally recommend against using RED unless you really understand the technology.  I would especially question using RED and FQ in the same class, as you do in class AF21.

I currently have this setup on my outside interface (connecting to PE) and have the service policy set on output (egress). 

I have found that large data transfers of default-class traffic is still able to overwhelm the link and the resereved bandwidth percentages to not seem to be able to protect the data in those classes.

You describe connecting to a PE, so this is not a p2p link?  If you're working across some kind of cloud technology, just setting QoS, even correctly, on the egress to cloud interface might be insufficient.  Might you describe your WAN environment?

As you mention default-class traffic, but you didn't post a default-class, you're just using the implicit default settings for this class?

As you're using NBAR and FQ in a named class, I assume you're working with a software based router using post HQF QoS, but identification of the actual platform and IOS version being used, might also be helpful.