IPv6 Routing Policies Explained
Key Concepts
IPv6 routing policies involve several key concepts:
- Policy-Based Routing (PBR)
- Route Maps
- Prefix Lists
1. Policy-Based Routing (PBR)
Policy-Based Routing (PBR) in IPv6 allows administrators to control the flow of traffic based on specific policies rather than just the destination address. This is particularly useful for directing traffic based on source addresses, application types, or other criteria.
Example: In a corporate network, you might want to route all traffic from the HR department to a specific server. Using PBR, you can create a policy that matches traffic from the HR subnet and directs it to the designated server, regardless of the destination address.
2. Route Maps
Route Maps are used to define complex routing policies in IPv6. They allow for the creation of rules that can match specific criteria and apply actions such as permitting or denying routes, setting metrics, or redistributing routes.
Example: Suppose you want to prefer routes from a specific ISP over others. You can create a route map that matches routes from that ISP and sets a lower metric, ensuring that these routes are preferred in the routing table.
3. Prefix Lists
Prefix Lists are used to filter routes based on IPv6 prefixes. They can be used in conjunction with route maps to create more granular routing policies. Prefix lists allow for the inclusion or exclusion of specific prefixes or ranges of prefixes.
Example: If you want to allow only certain subnets to be advertised to external networks, you can create a prefix list that includes those subnets and use it in a route map to permit only those routes to be advertised.
Understanding these routing policy concepts is crucial for advanced network management in IPv6. By mastering Policy-Based Routing, Route Maps, and Prefix Lists, you can create sophisticated routing policies that enhance network performance and security.