Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

QoS Marking Packets

Hi,

I need to mark the packets than are transmitted by the Streaming Server, inserting the IPP value 3.

I will realize the following configuration:

access-list 99 permit 172.30.250.25 0.0.0.0

class-map match-all Traffic
match access-group 99
exit

policy-map Mark
class Traffic
set ip precedence 3
exit

interface fastethernet 0/0

service-policy output Mark

exit

Internet.jpg

Is this configuration correct?

Everyone's tags (3)
4 REPLIES
Silver

Re: QoS Marking Packets

looks good, that will mark the packets leaving the Core switch. Packets will lose the markings when they cross the Router, so you have to configure the router in the same way if you want the packets that are leaving the router to be marked also.

Siddhartha
New Member

QoS Marking Packets

Thanks for you answer SiddHartham.

I have some question.

1.- To keep the marks of IPP3 of leaving packets of Core Switch, I have to configure "mls wos trus  ip-precedence" in  the FE 0/1 of the Router A ?

2.- How I can check the labeling of the packets? (Wireshark, show commands).

Super Bronze

Re: QoS Marking Packets

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

Routers tend to leave ToS alone, unless you configure them to do otherwise.

For most Catalyst switches, they too leave ToS alone until you enable QoS where they will often reset to IPP 0, unless you configure otherwise.  You also might need an input policy to mark.  Many Catalyst switches don't offer all router QoS egress features.

Wireshark could confirm ToS contents.  Depending on where you want to check, next downstream device might be configured to match on IPP 3 and not do anything - i.e. compare counts to non-IPP 3.

Bronze

QoS Marking Packets

If your Core is router or L3 switch that supports router-style QoS, your configuration is correct. If it is a simple L3 switch (3560, 3750, etc.) than you have no possibility to do classification and marking on outbound direction. Then you need to do it inbound and you may apply it in port-based or VLAN-based fashion. In this case you also need to enable QoS (mls qos command) which automatically means setting CoS and DSCPs on all packets to zero unless it explicitly defined.

It is true concerning routers - they are transparent to IPP/DSCP unless explicitly configured to do something. And also you can not use mls qos trust command on a router - it is a switch-style command and is used on switchports only.

If you need to check labeling of a given packet - use Wireshark or debug ip packet detailed command with logging to buffer, then - show log to view packets.

1170
Views
7
Helpful
4
Replies