24-Port Fast Ethernet Switch Management Guide

C LASS OF S ERVICE C ONFIGURATION
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• 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 3-92 Setting IP Precedence/DSCP Priority Status
CLI – The following example enables IP Precedence service on the
switch.
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.
Console(config)#map ip precedence 4-262
Console(config)#
Table 3-14 Mapping IP Precedence
Priority Level Traffic Type Priority Level Traffic Type
7 Network Control 3 Flash
6 Internetwork Control 2 Immediate
5 Critical 1 Priority
4Flash Override0Routine