Users Guide

Show routing tables of VRFs( after route-export and route-import tags are configured).
Dell# show ip route vrf VRF-Red
O 11.1.1.1/32 via 111.1.1.1 110/0 00:00:10
C 111.1.1.0/24 Direct, Gi 1/11 0/0 22:39:59
O 44.4.4.4/32 via VRF-shared:144.4.4.4 0/0 00:32:36
C 144.4.4.0/24 Direct, VRF-shared:Gi 1/4 0/0 00:32:36
Dell# show ip route vrf VRF-Blue
O 22.2.2.2/32 via 122.2.2.2 110/0
00:00:11
C 122.2.2.0/24 Direct, Gi 1/12 0/0 22:39:61
O 44.4.4.4/32 via vrf-shared:144.4.4.4 0/0 00:32:36
C 144.4.4.0/24 Direct, vrf-shared:Gi 1/4 0/0 00:32:36
Dell# show ip route vrf VRF-Green
O 33.3.3.3/32 via 133.3.3.3 110/0
00:00:11
C 133.3.3.0/24 Direct, Gi 1/13 0/0 22:39:61
Dell# show ip route vrf VRF-Shared
O 11.1.1.1/32 via VRF-Red:111.1.1.1 110/0 00:00:10
C 111.1.1.0/24 Direct, VRF-Red:Gi 1/11 0/0 22:39:59
O 22.2.2.2/32 via VRF-Blue:122.2.2.2 110/0 00:00:11
C 122.2.2.0/24 Direct, VRF-Blue:Gi 1/22 0/0 22:39:61
O 44.4.4.4/32 via 144.4.4.4 110/0
00:00:11
C 144.4.4.0/24 Direct, Gi 1/4 0/0 00:32:36
Important Points to Remember
• If the target VRF conatins the same prefix as either the sourced or Leaked route from some other VRF, then route Leaking for that
particular prefix fails and the following error-log is thrown.
SYSLOG (“Duplicate prefix found %s in the target VRF %d”, address, import_vrf_id) with
The type/level is EVT_LOGWARNING.
• The source routes always take precedence over leaked routes. The leaked routes are deleted as soon as routes are locally learnt by the
VRF using other means.
• For recovery, you must take appropriate action either by deleting the unwanted prefixes or issuing clear command or both.
• In the target VRF, you cannot leak routes that are imported through the route leaking feature.
• The leaked route points to the next-hop of the source routes. You cannot do any modifications to the next-hop of the leaked route in
the destination VRF.
• IPv6 link local routes will never be leaked from one VRF to another.
Configuring Route Leaking with Filtering
When you initalize route leaking from one VRF to another, all the routes are exposed to the target VRF. If the size of the source VRF's
RTM is considerablly large, an import operation results in the duplication of the target VRF's RTM with the source RTM entries. To
mitigate this issue, you can use route-maps to filter the routes that are exported and imported into the route targets based on certain
matching criteria. These match criteria include, prefix matches and portocol matches.
You can use the match source-protocol or match ip-address commands to specify matching criteria for importing or
exporting routes between VRFs.
NOTE:
You must use the match source-protocol or match ip-address commands in conjunction with the route-map
command to be able to define the match criteria for route leaking.
Consider a scenario where you have created two VRF tables VRF-red and VRF-blue. VRF-red exports routes with the
export_ospfbgp_protocol route-map to VRF-blue. VRF-blue imports these routes into its RTM.
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Virtual Routing and Forwarding (VRF)