222
C
HAPTER
27: Q
O
S C
ONFIGURATION
You can select the priority trust mode of the port as you require.
In the mode of trusting the packet precedence, the switch can trust the following
priorities as you configure:
■
Trust the 802.1p priority of the packets
■
Trust the DSCP precedence of the packets
Trusting the 802.1p
priority of the Packets
You can specify whether to replace the precedence carried in the packet with the
mapped precedence when you configure to trust the 802.1p priority of the packet:
■
In the default mode, the switch does not replace the precedence carried in the
packet with the mapped precedence.
■
In the automap mode, the switch replaces the precedence carried in the packet
with the mapped precedence.
If the packet does not carry any precedence, the switch will perform the
corresponding mapping by using the port precedence to search for the “COS->other
priority mapping table”.
Figure 72
The mapping process of trusting 802.1p priority
Trusting the DSCP
Precedence of the
Packets
You can specify whether to replace the precedence carried in the packet with the
mapped precedence when you configure to trust the DSCP precedence of the packet:
■
In the default mode, the switch does not replace the precedence carried in the
packet with the mapped precedence.
■
In the automap mode, the switch replaces the precedence carried in the packet
with the mapped precedence.
■
In the remap mode, the switch firstly gets new DSCP precedence by the “DSCP-->
DSCP” mapping relationship, and then searches for the “DSCP-->other
precedence” mapping table through the new DSCP precedence and replaces the
precedence carried in the packet with the mapped precedence.
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
“COS
－
> other precedence” mapping table
Search for “COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
“COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
Search for “COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
“COS->other precedence” mapping table
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
“COS
－
> other precedence” mapping table
Search for “COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
“COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
Search for “COS-
according to the COS (802.1p precedence) and
assign other precedence for the packet
Packets
Packets
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
48
0
6
6
56
0
7
7
40
0
5
5
32
0
4
4
24
0
3
3
8
0
1
2
0
0
0
1
16
0
2
0
DSCP
Drop
Local -pre
802.1p
>
“COS->other precedence” mapping table
according to the COS (802.1p precedence) and
assign other precedence for the packet
Содержание 4200G 12-Port
Страница 10: ...8 CONTENTS...
Страница 14: ...4 ABOUT THIS GUIDE...
Страница 46: ...32 CHAPTER 5 LOGGING IN THROUGH WEB BASED NETWORK MANAGEMENT SYSTEM...
Страница 48: ...34 CHAPTER 6 LOGGING IN THROUGH NMS...
Страница 60: ...46 CHAPTER 9 VLAN CONFIGURATION...
Страница 64: ...50 CHAPTER 10 MANAGEMENT VLAN CONFIGURATION...
Страница 80: ...66 CHAPTER 13 GVRP CONFIGURATION...
Страница 98: ...84 CHAPTER 15 LINK AGGREGATION CONFIGURATION...
Страница 112: ...98 CHAPTER 18 MAC ADDRESS TABLE MANAGEMENT...
Страница 126: ...112 CHAPTER 19 LOGGING IN THROUGH TELNET...
Страница 162: ...148 CHAPTER 20 MSTP CONFIGURATION...
Страница 274: ...260 CHAPTER 29 IGMP SNOOPING CONFIGURATION...
Страница 276: ...262 CHAPTER 30 ROUTING PORT JOIN TO MULTICAST GROUP CONFIGURATION...
Страница 298: ...284 CHAPTER 33 SNMP CONFIGURATION...
Страница 304: ...290 CHAPTER 34 RMON CONFIGURATION...
Страница 338: ...324 CHAPTER 36 SSH TERMINAL SERVICES...
Страница 356: ...342 CHAPTER 38 FTP AND TFTP CONFIGURATION...
Страница 365: ...Information Center Configuration Example 351 S4200G terminal logging...
Страница 366: ...352 CHAPTER 39 INFORMATION CENTER...
Страница 378: ...364 CHAPTER 40 BOOTROM AND HOST SOFTWARE LOADING...
Страница 384: ...370 CHAPTER 41 Basic System Configuration and Debugging...
Страница 388: ...374 CHAPTER 43 NETWORK CONNECTIVITY TEST...
Страница 406: ...392 CHAPTER 45 CONFIGURATION OF NEWLY ADDED CLUSTER FUNCTIONS...
Страница 422: ...408 CHAPTER 48 UDP HELPER CONFIGURATION...
