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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 20 Configuring QoS
Configuring QoS
This example shows how to create a Layer 2 MAC ACL with two permit statements. The first statement
allows traffic from the host with MAC address 0001.0000.0001 to the host with MAC
address 0002.0000.0001. The second statement allows only Ethertype XNS-IDP traffic from the host
with MAC address 0001.0000.0002 to the host with MAC address 0002.0000.0002.
Switch(config)# mac access-list extended maclist1
Switch(config-ext-macl)# permit 0001.0000.0001 0.0.0 0002.0000.0001 0.0.0
Switch(config-ext-macl)# permit 0001.0000.0002 0.0.0 0002.0000.0002 0.0.0 xns-idp
! (Note: all other access implicitly denied)
Classifying Traffic by Using Class Maps
You use the class-map global configuration command to isolate a specific traffic flow (or class) from
all other traffic and to name it. The class map defines the criteria to use to match against a specific traffic
flow to further classify it. Match statements can include criterion such as an ACL, IP precedence values,
or DSCP values. The match criterion is defined with one match statement entered within the class-map
configuration mode.
Note
You can also create class-maps during policy map creation by using the class policy-map
configuration command. For more information, see the
“Classifying, Policing, and Marking Traffic
by Using Policy Maps” section on page 20-32
.
Beginning in privileged EXEC mode, follow these steps to create a class map and to define the match
criterion to classify traffic:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
mls qos
Enable QoS on the switch.
Step 3
access-list access-list-number {deny |
permit} source [source-wildcard]
or
access-list access-list-number {deny |
permit} protocol source [source-wildcard]
destination [destination-wildcard]
or
mac access-list extended name
{permit | deny} {host src-MAC-addr mask
| any | host dst-MAC-addr | dst-MAC-addr
mask} [type mask]
Create an IP standard or extended ACL for IP traffic or a Layer 2 MAC
ACL for non-IP traffic, repeating the command as many times as
necessary.
For more information, see the
“Classifying Traffic by Using ACLs”
section on page 20-27
.
Note
When creating an access list, remember that, by default, the
end of the access list contains an implicit deny statement for
everything if it did not find a match before reaching the end.
