User Guide

31-9
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
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Chapter 31 Configuring PFC QoS
Understanding How PFC QoS Works
Figure 31-5 Marking with PFC2 and Multilayer Switch Feature Card 2
Figure 31-6 Marking with PFC1 and Multilayer Switch Feature Card 1 or 2
55845
To egress
port
IP traffic
from PFC2?
Write ToS
byte into
packet
No
Ye s
Multilayer Switch Feature Card 2 (MSFC2) marking
From PFC2
Route
traffic
CoS =
IP precedence for
all traffic
(not configurable)
27107
To egress
port
IP traffic
from PFC?
Write ToS
byte into
packet
No
Ye s
Multilayer Switch Feature Card (MSFC) marking
From PFC
Route
traffic
CoS = 0 for all traffic
(not configurable)