Classification, Marking, And Policing With A Layer 3 Switching Engine - Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual

Understanding How QoS Works
Table 41-1 Marking Based on Per-Port Classification
Port Keyword ACE Keyword Marking Rule
untrusted
trust-ipprec
trust-dscp
trust-cos
QoS uses configurable mapping tables to set internal and egress DSCP, which is a 6-bit value, from CoS
and IP precedence, which are 3-bit values (for more information, see the
on page 41-15

Classification, Marking, and Policing with a Layer 3 Switching Engine

With a Layer 3 switching engine, the Catalyst 6000 family switches provide QoS only for the
Note
following frame types: Ethernet_II, Ethernet_802.3, Ethernet_802.2, and Ethernet_SNAP.
These sections describe classification, marking, and policing with a Layer 3 switching engine:
•
•
•
•
•
•
•
•
•
Note Classification with a Layer 3 switching engine uses Layer 2, 3, and 4 values. Marking with a Layer 3
switching engine uses Layer 2 CoS values and Layer 3 IP precedence or DSCP values.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
41-14
dscp
dscp
dscp
dscp
and the "Configuring DSCP Value Maps" section on page
Internal DSCP Values, page 41-15
ACLs, page 41-15
Named ACLs, page 41-16
Default ACLs, page 41-20
Marking Rules, page 41-21
Policing Rules, page 41-22
PFC2 Policing Decisions, page 41-23
Attaching ACLs, page 41-23
Final Layer 3 Switching Engine CoS and ToS Values, page 41-24
Set internal and egress DSCP as specified in the ACE.
For IP traffic, set internal and egress DSCP from the received Layer 3
IP precedence value. For other traffic, set internal and egress from the
received or port Layer 2 CoS value.
Note—With the trust-ipprec port keyword, QoS uses only the IP
precedence bits. If traffic with a DSCP value enters the switch through
a port configured with the trust-ipprec port keyword, the three most
significant bits of the DSCP value are interpreted as an IP precedence
value; QoS ignores the rest of the DSCP value.
For IP traffic, set internal and egress DSCP from the received Layer 3
DSCP value. For other traffic, set internal and egress DSCP from the
received or port Layer 2 CoS value.
Set internal and egress DSCP from the received or port Layer 2 CoS
value.
Chapter 41 Configuring QoS
"Internal DSCP Values" section
41-55).
78-13315-02