Create MPLS Policies

You can create a policy to add or change the top MPLS (Multiprotocol Label Switching) label on a packet. MPLS policies can be applied only to classes that have rate or priority policies.

You can also create a policy to change the experimental (EXP) bits field of the MPLS label.

Change MPLS Labels

There are three operations you can perform on outer (first) MPLS labels:

• pop — removes the top label of the MPLS stack
• swap — replaces the top label of the MPLS stack with a different label
• push — puts a label in a packet (and creates the stack if it doesn't exist)

A class can have a combination of push, swap, and pop operations in its MPLS policy. If more than one operation type is specified for a given class, they are executed in the following order: pop, swap, push. For example, a class might have a policy that specifies a swap, three pops, and a push. In this case, the three pops occur first, then the swap, and then the push.

Note: To perform this task from PolicyCenter, you must first select a unit or draft configuration in the Configurations window, then select the Class Tree tab from the right pane of this window.

To modify the top label on an MPLS class:

1. Open the priority or rate policy. (See Modify a Policy.)

2. Click MPLS in the Policy window. The Policy:MPLS window opens.  show screen

3. To pop off the top label of the MPLS stack, select the Pop checkbox and enter the number of times (1–8) you want to pop off the label.

4. To swap the top label of the MPLS stack with another label, select the Swap MPLS label checkbox and enter the label value (0–1048575).

5. To put an MPLS label in a packet, select the Push MPLS label checkbox and enter the label value (0–1048575).

6. Click OK.

7. Click apply changes in the Policy window.

Change MPLS Experimental Field

To mark the experimental (EXP) bits field of an MPLS packet:

1. Open the priority or rate policy. (See Modify a Policy.)

2. Click MPLS in the Policy window. The Policy:MPLS window opens.  Show screen

3. Select the Swap MPLS experimental field checkbox.

4. Enter the value (0–7).

5. Click OK.

6. Click apply changes in the Policy window.

See also:

Classify Traffic Based on MPLS