Junos - Shortening internet full bgp table

Question

I want to shorten internet full bgp table (450K records) in such a way to catch all prefixes from /0 to /21 as well as all prefixes of /22 or more which are not included within /0 - /21 prefix range.

Example 1:

10.0.8.0/21
10.0.8.0/22
10.0.12.0/22

In this case we want to match only the first one (10.0.8.0/21), other two (10.0.8.0/22, 10.0.12.0/22) need to be rejected since they are included in the first one.

Example 2:

11.0.8.0/21 - is not within the table
11.0.8.0/22 - is not within the table
11.0.8.0/23
11.0.10.0/23
11.0.12.0/22

In this case we want to match the last three prefix (11.0.8.0/23, 11.0.10.0/23, 11.0.12.0/22) since first two records are missing from the table

How do I achieve this?

Answer 1

You need to configure aggregate routes. It's not clear what version of JunOS you're running, but it is covered in the JunOS routing guide

[edit]
routing-options {
   rib **routing-table-name** {
      aggregate {
          defaults {
              **aggregate-options**;
          }
          route **destination-prefix** {
              policy **policy-name**; 
              **aggregate-options**; 
          }
      }
  }
}