Policy Marking can mark the IPP field or the entire ToS byte using the set command in the route map. When doing this the following sequence is used:
- Packets are examined as they enter an interface
- Route map is used to match subsets of packets
- Mark either the IPP or ToS byte using the set command
- the traditional policy routing function of the set command to define the route might also be configured but is not required.
Should only be used where CB Marking is unavailable or when a router needs to use both policy routing and mark packets entering the same interface.