How Map Groups Work; Creating Map Groups - Alcatel-Lucent OmniSwitch 6850-48 Network Configuration Manual

Using Map Groups

How Map Groups Work

When mapping from 802.1p to 802.1p, the action will result in remapping the specified values. Any values
that are not specified in the map group are preserved. In this example, a map group is created for 802.1p
bits.
-> policy map group Group2 1-2:5 4:5 5-6:7
-> policy action Map1 map 802.1p to 802.1p using Group2
The to and from values are separated by a colon (:). If traffic with 802.1p bits comes into the switch and
matches a policy that specifies the Map1 action, the bits will be remapped according to Group2. If the
incoming 802.1p value is 1 or 2, the value will be mapped to 5. If the incoming 802.1p value is 3, the
outgoing value will be 3 (the map group does not specify any mapping for a value of 3). If the incoming
802.1p value is 4, the value will be mapped to 5. If the incoming 802.1p value is 5 or 6, the value will be
mapped to 7.
When mapping to a different type of value, however (ToS/DSCP to 802.1p), any values in the incoming
flow that matches the rule but that are not included in the map group will be zeroed out. For example, the
following action specifies the same map group but instead specifies mapping 802.1p to ToS:
-> policy action Map2 map tos to 802.1p using Group2
In this case, if ToS traffic comes into the switch and matches a policy that specifies the Map2 action, the
ToS value will be mapped according to Group2 if the value is specified in Group2. If the incoming ToS
value is 2, the value will be mapped to 5; however, if the incoming value is 3, the switch will map the
value to zero because there is no mapping in Group2 for a value of 3.
Note. Ports on which the flow is mapped must be a trusted port; otherwise the flow will be dropped.

Creating Map Groups

To create a map group, use the
tosGroup, enter:
-> policy map group tosGroup 1-2:5 4:5 5-6:7
The to and from values are separated by a colon (:). For example, a value of 2 will be mapped to 5.
Note. Map group configuration is not active until the qos apply command is entered.
The remapping group may then be associated with a rule through the policy action command. In this
example, a policy condition called Traffic has already been configured.
-> policy action tosMap map tos to 802.1p using tosGroup
-> policy rule r3 condition Traffic action tosMap
To delete mapping values from a group, use no and the relevant values:
-> policy map group tosGroup no 1-2:4
The specified values will be deleted from the map group at the next qos apply.
page 40-52
policy action map command. For example, to create a map group called
OmniSwitch AOS Release 6 Network Configuration Guide
Configuring QoS
September 2009