System information

Configuring the Switch
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3
Mapping IP Precedence Priority
The Type of Service (TOS) octet in the IPv4 header includes three precedence bits
(see page 3-192) defining eight different priority levels ranging from highest priority
(7) for network control packets to lowest priority (0) for routine traffic. Bits 6 and 7 are
used for network control, and the other bits for various application types.
Precedence values are defined in the following table.
Command Attributes
• IP Precedence Priority Status – Enables or disables the IP Precedence priority.
• IP Precedence Priority Table
– Shows the IP Precedence to CoS map.
• Class of Queue Service Value
– Maps an IP Precedence value to a CoS queue.
Note that queue “0” represents low priority and “3” represent high priority.
Note:
IP Precedence priority settings apply to all interfaces.
Web – Click Priority, IP Precedence Priority Status. Set the IP Precedence Priority
Status to Enabled.
Figure 3-120 Globally Enabling the IP Precedence Priority Status
Table 3-15 Mapping IP Precedence Values to CoS Priority Queues
IP Precedence Value Traffic Type Default CoS Output Queue
0 Routine 0
1Priority 0
2 Immediate 1
3Flash 1
4Flash Override2
5Critical 2
6 Internetwork Control 3
7 Network Control 3