Priority Mapping; Priority Overview - H3C LS-3100-52P-OVS-H3 Operation Manual

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Priority Mapping

When configuring priority mapping, go to these sections for information you are interested in:

Priority Overview

Priority Mapping Overview
Configuring a Priority Mapping Table
Configuring the Port Priority
Configuring Port Priority Trust Mode
Displaying and Maintaining Priority Mapping
Priority Overview
The following describes several types of precedence:
1) IP precedence, ToS precedence, and DSCP precedence
Figure 3-1 DS field and ToS field
The ToS field in an IP header contains eight bits, which are described as follows:
The first three bits indicate IP precedence in the range of 0 to 7.
Bit 3 to bit 6 indicate ToS precedence in the range of 0 to 15.
RFC2474 re-defines the ToS field in the IP packet header, which is called the DS field. The first six
(bit 0 to bit 5) bits of the DS field indicate DSCP precedence in the range of 0 to 63. The last two bits
(bit 6 and bit 7) are reserved bits.
Table 3-1 Description on IP Precedence
IP Precedence (decimal)
0
1
2
3
4
5
IP Precedence (binary)
000
001
010
011
100
101
3-1
Description
Routine
priority
immediate
flash
flash-override
critical