QoS Marking on Cisco IOS Router

This topic is to discuss the following lesson:

Hi Rene,

Why only switches and wireless devices are used to configure for re-marking traffic?
We do it for qos traffic confidentiality ?
The PHB logic is setting QoS marking for every devices right ? According to that do we need to re- match the traffics along the way , I am not clear about that…

Thnx , Thnx & Thnx again
Deniz

Hi Deniz,

Marking is typically done on the “border” of our network. This could be an IP phone or the switch or router that first receives these packets.

Once the packets are marked, there’s no need to do this again. You can trust the markings and apply an action to it (queuing, policing, shaping, etc.). The only reason to re-mark packets is if you don’t trust your traffic.

Rene

Thnx Rene,

You are best !
Deniz

thankyou v much rene !

Hi, Rene.

Reading this tutorial I had a doubt: what is the difference of I configure the command set precedence and set ip precedence or even if it was set dscp or set ip dscp into the policy-map? What changes in time of the router should mark the packet?

Thank you in advance

Hello Stafanio

According to Cisco, the set ip dscp command was replaced with the set dscp command:

set dscp - 12.2(13)T - This command was introduced. It replaced the set ip dscp command.

Similarly, the set ip precedence command was replaced with the set precedence command:

set precedence - 12.2(13)T This command was introduced. This command replaces the set ip precedence command.

More information about these commands from Cisco can be found here.

I hope this has been helpful!

Laz

Would it be possible for you to provide marking examples using ECN and CoS?

Hi Chris,

I’ll add ECN (RED/WRED) for sure.

What would you like to know about CoS? It’s similar to DSCP/ IP Precedence but it’s marking on L2 when you use 802.1Q:

Rene

Is it possible for you to cover Layer 2 QoS in more detail?

Just going off the blueprint you are expected to know queueing, scheduling, classifcation and marking techniques

Hello Chris.

All of Rene’s lessons concerning Layer 2 QoS can be found under Unit 2 of the Quality of Service course coverage found at the following link:


Unit 2 is titled “LAN QoS” and includes all the L2 QoS found on NetworkLessons.

If you would like something more specific or more detailed than this, feel free to make a suggestion on the Lesson Ideas page found below.


I hope this has been helpful!

Laz

You need static routes for this lab to work or some kind of routing

r1 192.168.23.0 255.255.255.0 192.168.12.2
r3 192.168.12.0 255.255.255.0 192.168.23.2

Hello Evan

Yes, you are correct, those static routes should be indicated in the configurations at the end. I will let Rene know.

Thanks for catching that!

Laz