This will be the intro to the pointers or theoretical stuff to know before diving into configuration and troubleshooting. On Chris’s initial Topology he has 3 routers connected on one common subnet, so I will need to review the configuration’s to understand what the actual networks are or if there is a reason he did that, so stay tuned for a Topology update.
There are quite a few VERY important details to PBR, and I don’t want to them to get lost or buried in sentences, so here are the facts on Policy Routing and Local Policy Routing:
- Policy Routing does not effect the final destination of traffic but rather what path it takes to get to that final destination
- Policy Routing applies to incoming traffic to the router, Local Policy Routing is working with traffic that is created on the local router itself, not incoming traffic
- If configured on a specified interface, it will only effect traffic incoming traffic to that interface and leave all other traffic to the normal routing process
- Can route based upon both source address, destination address, etc, so Extended Access-Lists are usually the most effect way to achieve Policy Routing
The next two I need to group together for clarity sake as to why they belong together, but I advise, but you may need to read the next one a couple of times for it to really sink in:
- If traffic DOES NOT match any permit lines in a route-map, but DOES match a deny line, that traffic is sent to the routing process for normal routing
- If you want traffic that DOES NOT match any permit or deny lines in the route-map to be discarded and not sent to routing process, you must create a catch-all clause at the end of the route-map sending traffic to Null0
That is it for tonight, I will update once it is configuration time!