SMC Networks SMC6752AL2 manual 175, Selecting IP Precedence/DSCP Priority, Mapping IP Precedence

CLASS OF SERVICE CONFIGURATION

Selecting IP Precedence/DSCP Priority

The switch allows you to choose between using IP Precedence or DSCP priority. Select one of the methods or disable this feature.

Command Attributes

•Disabled – Disables both priority services. (This is the default setting.)

•IP Precedence – Maps layer 3/4 priorities using IP Precedence.

•IP DSCP – Maps layer 3/4 priorities using Differentiated Services Code Point Mapping.

Web – Click Priority, IP Precedence/DSCP Priority Status. Select Disabled, IP Precedence or IP DSCP from the scroll-down menu, then click Apply.

Figure 3-76 IP Precedence/DSCP Priority Status

CLI – The following example enables IP Precedence service on the switch.

Console(config)#map ip precedence	4-229
Console(config)#

Mapping IP Precedence

The Type of Service (ToS) octet in the IPv4 header includes three precedence bits defining eight different priority levels ranging from highest priority for network control packets to lowest priority for routine traffic. The default IP Precedence values are mapped one-to-one to Class of Service values (i.e., Precedence value 0 maps to CoS value 0, and so forth). Bits 6 and 7 are used for network control, and the other bits for various application types. ToS bits are defined in the following table.

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