Class of Service Configuration 3

CLI – The following example globally enables IP Precedence service on the switch, maps IP Precedence value 1 to CoS value 0 (on port 1), and then displays the IP Precedence settings.

Console(config)#map

ip precedence

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Console(config)#interface

ethernet 1/1

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Console(config-if)#map ip

precedence 1 cos 0

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Console(config-if)#end

 

 

 

Console#show map ip

precedence ethernet 1/1

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Precedence

mapping status: disabled

 

Port

Precedence COS

 

 

---------

---------- ---

 

 

Eth 1/ 1

 

0

0

 

 

Eth 1/ 1

 

1

0

 

 

Eth 1/ 1

 

2

2

 

 

Eth 1/ 1

 

3

3

 

 

Eth 1/ 1

 

4

4

 

 

Eth 1/ 1

 

5

5

 

 

Eth 1/ 1

 

6

6

 

 

Eth 1/ 1

 

7

7

 

 

Console#

 

 

 

 

 

*Mapping specific values for IP Precedence is implemented as an interface configuration command, but any changes will apply to the all interfaces on the switch.

Mapping DSCP Priority

The DSCP is six bits wide, allowing coding for up to 64 different forwarding behaviors. The DSCP replaces the ToS bits, but it retains backward compatibility with the three precedence bits so that non-DSCP compliant, ToS-enabled devices, will not conflict with the DSCP mapping. Based on network policies, different kinds of traffic can be marked for different kinds of forwarding. The DSCP default values are defined in the following table. Note that all the DSCP values that are not specified are mapped to CoS value 0.

Table 3-15 Mapping DSCP Priority
IP DSCP ValueCoS Value

 

 

0

0

8

1

10, 12, 14, 16

2

18, 20, 22, 24

3

26, 28, 30, 32, 34, 36

4

38, 40, 42

5

48

6

46, 56

7

Command Attributes

•DSCP Priority Table – Shows the DSCP Priority to CoS map.

•Class of Service Value – Maps a CoS value to the selected DSCP Priority value. Note that “0” represents low priority and “7” represent high priority.

Note: IP DSCP settings apply to all interfaces.

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