Chapter 18
| Class of Service Commands
Priority Commands (Layer 3 and 4)
– 437 –
◆
Two QoS domains can have different DSCP definitions, so the DSCP-to-PHB/
Drop Precedence mutation map can be used to modify one set of DSCP values
to match the definition of another domain. The mutation map should be
applied at the receiving port (ingress mutation) at the boundary of a QoS
administrative domain.
◆
Random Early Detection starts dropping yellow and red packets when the
buffer fills up to 0x60 packets, and then starts dropping any packets regardless
of color when the buffer fills up to 0x80 packets.
Example
This example changes the priority for all packets entering port 1 which contain a
DSCP value of 1 to a per-hop behavior of 3 and a drop precedence of 1. Referring to
Table 97
, note that the DSCP value for these packets is now set to 25 (3x2
3
+1) and
passed on to the egress interface.
Console(config)#qos map dscp-mutation 3 1 from 1
Console(config)#
qos map phb-queue
This command determines the hardware output queues to use based on the
internal per-hop behavior value. Use the
no
form to restore the default settings.
Syntax
qos map phb-queue
queue-id
from
phb0 ... phb7
no map phb-queue
phb0 ... phb7
phb
- Per-hop behavior, or the priority used for this router hop. (Range: 0-7)
queue-id
- The ID of the priority queue. (Range: 0-7, where 7 is the highest
priority queue)
D
EFAULT
S
ETTING
Command Mode
Global Configuration
Command Usage
◆
Enter a queue identifier, followed by the keyword “from” and then up to eight
internal per-hop behavior values separated by spaces.
◆
Egress packets are placed into the hardware queues according to the mapping
defined by this command.
Table 98: Mapping Internal Per-hop Behavior to Hardware Queues
Per-hop Behavior
0
1
2
3
4
5
6
7
Hardware Queues
1
0
0
1
2
2
3
3
Summary of Contents for EX-3524
Page 2: ......
Page 28: ...Figures 28 ...
Page 34: ...Section I Getting Started 34 ...
Page 58: ...Chapter 1 Initial Switch Configuration Setting the System Clock 58 ...
Page 72: ...Chapter 2 Using the Command Line Interface CLI Command Groups 72 ...
Page 156: ...Chapter 5 SNMP Commands Notification Log Commands 156 ...
Page 164: ...Chapter 6 Remote Monitoring Commands 164 ...
Page 218: ...Chapter 7 Authentication Commands Management IP Filter 218 ...
Page 268: ...Chapter 8 General Security Measures Port based Traffic Segmentation 268 ...
Page 292: ...Chapter 9 Access Control Lists ACL Information 292 ...
Page 312: ...Chapter 10 Interface Commands Power Savings 312 ...
Page 324: ...Chapter 11 Link Aggregation Commands Trunk Status Display Commands 324 ...
Page 366: ...Chapter 15 Address Table Commands 366 ...
Page 428: ...Chapter 17 VLAN Commands Configuring Voice VLANs 428 ...
Page 572: ...Chapter 25 IP Interface Commands IPv6 Interface 572 ...
Page 578: ...Section I Appendices 578 ...