QOS: Configuring Policing using the access-list rate-limit command

Let’s say you have a scenario that says we want to configure R2 such that all inbound traffic marked with an IP precedence of 5 and 3 should be limitied to a maximum of 1Mbps. Anything above this rate should be discarded.

Sounds simple enough. What are the different IOS tools that you can accomplish this?

QOS: Applying CBWFQ to a sub-interface

By default IOS does not let you apply CBWFQ directly to a sub interface. I ran into this scenario and worked my way around it in a workbook lab (IE Workbook Vol 2 - Lab 15). I thought it was pretty cool and hopefully it helps someone else out..

Tutorial: What is the difference between bandwidth percent and bandwidth remaining percent?

One of the most common questions that CCIE candidates face when studying QOS MQC for the lab is “What is the difference between bandwidth percent and bandwidth remaining percent?”. Both are used in CBWFQ when implementing congestion management but what is the difference? The answer to this questions are the focus of this tutorial.

Tutorial: How to use Cisco MQC & NBAR to filter websites like Youtube

Thanks for visiting! If you’re new here, you may want to subscribe to my RSS feed. This blog posts regular tutorials, news, and study tips about networking, especially about Cisco CCIE related topics. Go ahead, subscribe to the feed! You can also receive updates from this blog via email. Thanks for visiting!I was asked a [...]

CCIE QoS Mind Map

Whats On Your Mind - Using Mind Maps for study.
I was playing around with Mindomo (which is an awesome online mind map creator) and I whipped up a QoS mind map. The interface for Mindomo takes a bit of getting used to, but its a fantastic study tool. Mind maps are a great way to [...]

Implementing Weighted Fair Queing, Part II

But Wait…theres still more! QoS Group based WFQ
In my previous article on WFQ, we really only talked about flow based WFQ. Flow based WFQ automatically sorts out traffic flows or conversations into separate queues. Smaller flower get precedence over larger flow. But what about frames that are classified with a QoS marking. If we have [...]

Implementing Weighted Fair Queuing

Fairness for the Little Guy.
Weighted Fair Queue (WFQ) is another congestion management strategy. It is very different from the other two congestion management strategies we have looked at (PQ and CQ), in that it does not need classification options configured. Traffic is automatically sorted and put into different queues without any kind of access-list [...]

CAR & CIR - What the hell is the difference?

What is the difference?
When we are talking about Committed Information Rate we are usually talking about Traffic Shaping. This is especially true of Frame Relay Traffic Shaping (FRTS). In FRTS we might configure a CIR with the frame-relay cir command:
For example:
interface serial0
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 200
class adjust_vc_class_rate
!
map-class frame-relay adjust_vc_class_rate
frame-relay cir [...]

Configuring Custom Queuing

In my previous post, I talked a little bit about congestion management focusing on priority queuing. Priority queuing is great in making sure that VIP traffic gets to looked first dibs on that output queue when congestion occurs. The problem with priority queuing was starvation. If there was frames always waiting in the high queue [...]

Configuring Priority Queuing

What is Congestion Management?
Priority Queuing is a QoS congestion management mechanism. What the hell is a congestion management mechanism I hear you ask? Congestion management is how a router deals with what happens when its output queue is full. A router can’t really do much to control traffic, all it does is collect frames, figure [...]