Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 727

Chapter 41 Configuring QoS
Marking Rules
Marking is not supported for IPX or MAC traffic with a PFC2.
Note
Marking rules specify how QoS marks traffic when the traffic matches the filtering parameters in an
ACE (see the
supports four marking rules, specified with the following four ACE keywords: trust-dscp, trust-ipprec,
trust-cos, and dscp. Each ACE contains one of the keywords. The marking rules are as follows:
•
•
•
•
QoS uses configurable mapping tables to set the DSCP value, which is 6 bits, from CoS and IP
precedence, which are 3-bit values (for more information, see the
Internal DSCP Values" section on page 41-55
Internal DSCP Values" section on page
78-13315-02
"ACE Name, Marking Rule, Policing, and Filtering Syntax" section on page
trust-dscp (IP ACLs only)—Instructs QoS to set internal and egress DSCP from received DSCP
values (see the "Internal DSCP Values" section on page
trust-ipprec (IP ACLs only)—Instructs QoS to set internal and egress DSCP from received IP
precedence values.
With the trust-ipprec port keyword, QoS uses only the IP precedence bits. If traffic with
Note
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.
trust-cos (all ACLs except IPX and MAC with a PFC2)—Instructs QoS to set internal and egress
DSCP from received or port CoS values. In traffic from ports configured with the trust-cos
keyword, the CoS value is that received in ISL and 802.1Q frames; in all other cases, the CoS value
is that configured on the port (default is zero).
dscp (all ACLs except IPX and MAC with a PFC2)—Instructs QoS to mark traffic as indicated by
the port trust keywords:
– In IP traffic from ingress ports configured with the trust-dscp port keyword, the dscp ACE
keyword instructs QoS to set the internal and egress DSCP values from the received DSCP
values. In non-IP traffic, QoS sets the DSCP from the received or port CoS value.
In IP traffic from ingress ports configured with the trust-ipprec port keyword, the dscp ACE
–
keyword instructs QoS to set the internal and egress DSCP values from the received IP
precedence values. In non-IP traffic, QoS sets the DSCP value from the received or port CoS
value.
– In traffic from ingress ports configured with the trust-cos port keyword, the dscp ACE keyword
instructs QoS to set the internal and egress DSCP values from the received or port CoS values.
– In traffic from ingress ports configured with the untrusted port keyword, the dscp ACE
keyword instructs QoS to set the internal and egress DSCP values from the DSCP value in the
ACE.
The default configuration of the ACEs in the default ACLs contains the dscp ACE
Note
keyword, which supports per-port classification of traffic. With the default values, the
ACEs in the default ACLs apply DSCP zero to traffic from ingress ports configured with
the untrusted port keyword.
and the "Mapping Received IP Precedence Values to
41-56).
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
Understanding How QoS Works
41-15).
"Mapping Received CoS Values to
41-37). QoS
41-21