Cisco Cisco IOS Software Release 12.2(27)SBC

A VLAN-group is a traffic class that potentially consists of multiple IEEE 802.1Q VLAN subinterfaces. 
A class map defines the VLAN group and the match criteria the router uses to classify the traffic as 
belonging to a specific VLAN group. All of the subinterfaces belonging to a VLAN group share the 
bandwidth allocated to the group and share the same class queue.

The match vlan command allows you to specify the VLANs you want to include in a VLAN group. The 
configuration of a VLAN group can include individual VLAN ID values or a range of values. For 
example, VLANs with IDs 3, 5-8, and 10 can form a VLAN group. The router treats the VLANs 
specified in a VLAN group as an aggregate whole.

If you specify the match vlan command in a class map, you cannot specify other match commands in 
the same class map. Use the match vlan command only for VLAN grouping.

Only Ethernet, Fast Ethernet, and Gigabit Ethernet interfaces support VLAN groups. For outbound 
VLAN tag-based policies, use a shape command for each VLAN group.

A VLAN-group policy map defines QoS services for traffic classes that consists of multiple IEEE 
802.1Q VLAN subinterfaces (see the 

). In this way, you can apply a 

single QoS policy to multiple VLANs belonging to specific VLAN-group classes.

You can attach a VLAN-group policy map to only the main interface. The subinterfaces on the main 
interface inherit the service policy. 

The amount of policy space used is equivalent to the number of VLAN groups defined in the policy, 
including the VLAN groups defined in match-VLAN class maps and in the class-default class. The limit 
of available policy space is equivalent to 4096 policy maps.

Adding or removing VLAN-group classes from a VLAN-group policy only affects QoS on the 
subinterfaces that you added or removed from the policy. Adding or removing class-default classes 
affects QoS only on the subinterfaces that do not belong to any VLAN group. 

Modifying a child policy that is applied to a VLAN-group class in a VLAN-group policy affects QoS on 
all of the subinterfaces that belong to that VLAN group. Modifying a child policy applied to a 
class-default class affects QoS on all of the subinterfaces that do not belong to any VLAN group.

For more information, see the 

,

The VLAN ID is a number you specify to identify a VLAN subinterface. The router uses the VLAN ID 
of packets to classify them as belonging to specific VLAN groups. Valid VLAN ID values are from 1 to 
4094.