There is alot of confusion regarding the subject. In order to better understand the difference I will perform several tests with both RIB types.

First, we will test export-rib. Juniper’s KB16133 defines the export-rib as such:

“The export-rib command tells the router, from which tables to take information. For any individual RIB group, only one table can be specified in the export-rib statement.”

This means that export-rib should only work with exchanging routes between two tables.

To test export-rib groups we will attempt the following configurations:

Apply an export-rib group to a table to verify export-rib is working as intended
Apply an export-rib group to the same table which it’s configured for
Apply an export-rib group to multiple tables

Secondly, we will test import-rib. Juniper’s KB16133 defines the import-rib as such:

“Conversely, the import-rib command tells the router, into which tables to place information. Unlike its counterpart, the import-rib statement can specify multiple route tables.”

In the same KB article explains that the first routing table in an import-rib group is the source routing table and each subsequent routing table(s) are destination routing tables. This implies that the first routing table defined will be copied to the destination tables listed after. Jack Parks also concluded the same reasoning on the j-net forums.

To test import-rib groups we will attempt the following configurations.

Apply an import-rib group to a table to verify it’s working as intended (include source and destination tables).
Apply the import-rib group to the source table
Only provide a source table but no destinations table
Apply the import-rib to a different table than the source (a table not listed in the group)
Define multiple destination tables in the group and assign the group to a single table
Define multiple destination tables in the group and assign the group to a multiple table.
Do routes that are present in the routing table because of a RIB group qualify to then be copied to another routing table?

If you're looking for the results, they're at the bottom of this post. Otherwise, continue on for a long winded post

Initial configuration:

[edit]
root@srx-core# show interfaces
ge-0/0/0 {
    unit 0 {
        family inet {
            address 192.168.1.200/24;
        }
    }
}
ge-0/0/1 {
    vlan-tagging;
    unit 0 {
        vlan-id 200;
        family inet {
            address 10.100.0.1/24;
        }
    }
    unit 1 {
        vlan-id 201;
        family inet {
            address 10.101.1.254/24;
        }
    }
    unit 2 {
        vlan-id 202;
        family inet {
            address 10.101.2.254/24;
        }
    }
    unit 3 {
        vlan-id 203;
        family inet {
            address 10.101.3.254/24;
        }
    }
    unit 4 {
        vlan-id 204;
        family inet {
            address 10.101.4.254/24;
        }
    }
    unit 11 {
        vlan-id 11;
        family inet {
            address 172.16.1.1/24;
        }
    }
    unit 12 {
        vlan-id 12;
        family inet {
            address 172.16.2.1/24;
        }
    }
}
 
[edit]
root@srx-core# show routing-instances
test1 {
    instance-type virtual-router;
    interface ge-0/0/1.11;
}
test2 {
    instance-type virtual-router;
    interface ge-0/0/1.12;
}

Export-rib Test 1

Apply an export-rib group to a table to verify export-rib is working as intended

[edit]
root@srx-core# set routing-options rib-groups export-test export-rib test1.inet.0
 
[edit]
root@srx-core# set routing-instances test2 routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# commit
[edit routing-instances test2 routing-options interface-routes]
  'rib-group'
    export-test: primary rib for instance test2 was not found in ribgroup configuration.
error: configuration check-out failed

Well that’s strange. Let’s see if we can use the same group in the test1.inet.0 table

[edit]
root@srx-core# delete routing-instances test2 routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# set routing-instances test1 routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# commit
[edit routing-instances test1 routing-options interface-routes]
  'rib-group'
    export-test: primary rib for instance test1 was not found in ribgroup configuration.
error: configuration check-out failed

[edit]
root@srx-core# delete routing-instances test1 routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# set routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# commit
commit complete
 
Well it committed without errors. Let’s look at the routing tables and see what happened:
[edit]
root@srx-core# run show route table test1.inet.0
 
test1.inet.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
 
172.16.1.0/24      *[Direct/0] 17:38:42
                    > via ge-0/0/1.11
172.16.1.1/32      *[Local/0] 17:38:42
                      Local via ge-0/0/1.11
 
[edit]
root@srx-core# run show route table inet.0
 
inet.0: 15 destinations, 15 routes (15 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
 
10.0.0.0/24        *[OSPF/10] 21:43:04, metric 12
                    > to 192.168.1.1 via ge-0/0/0.0
10.0.1.16/28       *[OSPF/10] 21:43:04, metric 11
                    > to 192.168.1.1 via ge-0/0/0.0
10.100.0.0/24      *[Direct/0] 21:43:11
                    > via ge-0/0/1.0
10.100.0.1/32      *[Local/0] 21:43:13
                      Local via ge-0/0/1.0
10.101.1.0/24      *[Direct/0] 21:43:11
                    > via ge-0/0/1.1
10.101.1.254/32    *[Local/0] 21:43:13
                      Local via ge-0/0/1.1
10.101.2.0/24      *[Direct/0] 21:43:11
                    > via ge-0/0/1.2
10.101.2.254/32    *[Local/0] 21:43:13
                      Local via ge-0/0/1.2
10.101.3.0/24      *[Direct/0] 21:43:11
                    > via ge-0/0/1.3
10.101.3.254/32    *[Local/0] 21:43:13
                      Local via ge-0/0/1.3
10.101.4.0/24      *[Direct/0] 21:43:11
                    > via ge-0/0/1.4
10.101.4.254/32    *[Local/0] 21:43:13
                      Local via ge-0/0/1.4
192.168.1.0/24     *[Direct/0] 21:43:11
                    > via ge-0/0/0.0
192.168.1.200/32   *[Local/0] 21:43:13
                      Local via ge-0/0/0.0
224.0.0.5/32       *[OSPF/10] 21:43:22, metric 1
                      MultiRecv
 
[edit]
root@srx-core#

It appears there has been no change in either the routing table used in the rib group or the table to which it was applied.

[edit]
root@srx-core# delete routing-options interface-routes
 
[edit]
root@srx-core# set routing-options rib-groups export-test export-rib inet.0
 
[edit]
root@srx-core# set routing-instances test1 routing-options interface-routes rib-group inet export-test
 
[edit]
root@srx-core# commit
[edit routing-instances test1 routing-options interface-routes]
  'rib-group'
    export-test: primary rib for instance test1 was not found in ribgroup configuration.
error: configuration check-out failed

Well that was a waste of time.

Export-rib rule #1 : They don’t work
Export-rib rule #2 : The Junos Enterprise Routing book doesn’t even mention the existence of export-rib groups
Export-rib rule #3 : Searching Google for export-rib examples is futile

Let’s move on to something at least productive.

All Blogposts

Export-rib Test 1