Which BGP attributes can be used in apply clauses of a route-policy?

In the context of BGP (Border Gateway Protocol), the Local-Preference attribute is pivotal in influencing route selection within an autonomous system. It is specifically designed to determine which path is preferred for outbound traffic. When applied in a routing policy, Local-Preference has the effect of guiding routers to use a particular exit point for forwarding packets, thereby optimizing traffic according to the network's design requirements.

When creating a route-policy, the use of Local-Preference in apply clauses allows network engineers to define policies that directly impact how routes are selected based on their preference values. By modifying this attribute, network operators can ensure that certain routes are favored over others, thereby achieving load balancing and redundancy based on organizational needs.

While other attributes such as Tag, Multi-Exit Discriminator (MED), and AS Path do play roles in route selection and influence BGP behavior, they do not offer the same level of control over routing decisions within an AS when integrated into the apply clauses of a route-policy. This distinction makes Local-Preference a crucial tool in effective BGP routing management.