Redistribution loops

varyes

I am getting ready for my JNCIE-SP lab in few months and have a question.
To prevent loops when perform mutual route redistribution what approach are you using to keep policy simple?

Different approaches can be used depends on the task and combination of export policy (with tags) with filtering routes through import policy (using "from next-hop" or "route-filter" matching conditions) are most common to achieve optimal path.

Other methods can be used are adjusting the global preferences combined with export policy or writing an export policy combined with the route preference modification before it's installed in the routing table.

Junos software routing policy is extremely flexible and because of this there maybe many solutions for most of the problems. Unfortunately, this flexibility can work both ways which means there are many ways to break the network through mistakes in the policy.