From: san (san.study@gmail.com)
Date: Sun Jun 25 2006 - 14:27:27 ART
Hi ,
Could you help me by answering the following questions:
Question 1:
----------------
Is "mls qos trust cos" mandatory for using this command "mls qos cos 5"
under a Interface ?
Question 2:
------------------
In the below example , Is "trust dscp" mandatory before modifying the dscp
in policed-dscp-transmit ??
Example from :
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12225se/3550scg/swqos.htm
This example shows how to create a policy map and attach it to an ingress
interface. In the configuration, the IP standard ACL permits traffic from
network 10.1.0.0. For traffic matching this classification, the DSCP value
in the incoming packet is trusted. If the matched traffic exceeds an average
traffic rate of 48000 bps and a normal burst size of 8000 bytes, its DSCP is
marked down (based on the policed-DSCP map) and sent:
Switch(config)# *access-list 1 permit 10.1.0.0 0.0.255.255
*
Switch(config)# *class-map ipclass1
*
Switch(config-cmap)# *match access-group 1
*
Switch(config-cmap)# *exit
*
Switch(config)# *policy-map flow1t
*
Switch(config-pmap)# *class ipclass1
*
Switch(config-pmap-c)# *trust dscp ===========> IS IT
MANDATORY TO TRUST BEFORE MODIFYING DSCP ??
*
Switch(config-pmap-c)# *police 48000 8000 exceed-action policed-dscp-transmit
*
Switch(config-pmap-c)# *exit
*
Switch(config-pmap)# *exit
*
Switch(config)# *interface gigabitethernet0/1
*
Switch(config-if)# *service-policy input flow1t
*
Question 3:
------------------
In the below example can i assume, "trus dscp" is not manadatory ??t
This example shows how to create a policy map and attach it to an ingress
interface. In the configuration, the IP extended ACL permits TCP traffic
with an IP precedence of 4 from any host destined for the host at 224.0.0.5.
For traffic matching this classification, the DSCP value in the incoming
packet is set to 63.
Switch(config)# *access-list 104 permit tcp any host 224.0.0.5 precedence 4
*
Switch(config)# *class-map ipclass1
*
Switch(config-cmap)# *match access-group 104
*
Switch(config-cmap)# *exit
*
Switch(config)# *policy-map ip104
*
Switch(config-pmap)# *class ipclass1
*
Switch(config-pmap-c)# *set dscp 63
*
Switch(config-pmap-c)# *exit
*
Switch(config-pmap)# *exit
*
Switch(config)# *interface gigabitethernet0/1
*
Switch(config-if)# *service-policy input ip104
*
Question 4:
----------------
In the below example, Can I trust the COS and manipulate the DSCP on the
same interface ? . So the above examples where trust dscp, cos values of
outgoing packets will be zero ?
Switch(config)# *policy-map macpolicy1
*
Switch(config-pmap)# *class macclass1
*
Switch(config-pmap-c)# *set dscp 63
*
Switch(config-pmap-c)# *exit
*
Switch(config-pmap)# *class macclass2
*
Switch(config-pmap-c)# *set dscp 45
*
Switch(config-pmap-c)# *exit
*
Switch(config-pmap)# *exit
*
Switch(config)# *interface gigabitethernet0/1
*
Switch(config-if)# *mls qos trust cos
*
Switch(config-if)# *service-policy input macpolicy1
*
-- Thanks & Rgds SAN
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:33 ART