VRF Lite Route Leaking

[abhayjoshi07]

I have implemented VRF Lite on Cisco 9410 switch. There are two VRF's "XYZ" & "ABC" configured on the switch. I have a situation in which I have to leak overlapping IPv4 routes between the 2 VRFs. 

How do I do it and what will be the best solution to this problem.

[Georg Pauwen]

Hello,

below is a generic sample for importing one route:

ip routing
!
ip vrf XYZ
rd 100:1
route-target both rd 100:1
import map IMPORT_MAP_FROM_ABC
export map EXPORT_MAP_TO_ABC
!
ip vrf ABC
rd 200:2
route-target both rd 200:2
import map IMPORT_MAP_FROM_XYZ
export map EXPORT_MAP_TO_XYZ
!
interface GigabitEthernet 1/0/1
ip vrf forwarding XYZ
!
interface GigabitEthernet 1/0/2
ip vrf forwarding ABC
!
route-map IMPORT_MAP_FROM_ABC permit 10
match ip address prefix-list IMPORT_PREFIX_FROM_ABC
!
ip prefix-list IMPORT_PREFIX_FROM_ABC seq 5 permit 192.168.1.0/24

[abhayjoshi07]

@ Georg, How do we leak routes which are overlapping on both the VRF's.

[Georg Pauwen]

Hello,

how are the routes overlapping ? Can you post the routes you are trying to leak ?

[abhayjoshi07]

On the L3 switch I have a 10.10.10.0/24 subnet configured on a SVI which is already being used for servers and it belongs to VRF "XYZ". On the other hand I have a subnet 10.10.10.0/23 that is being learnt via OSPF which is in vrf "ABC". These VRFs were created after some reorganisations and cant change the subnets since these are already in production. Now I want to inject the route 10.10.10.0/24 in VRF "ABC" so that the servers are accessible but for obvious reasons cant do. Is it possible to NAT the subnet 10.10.10.0/24 to a different subnet after it is injected into VRF "ABC" ?

[Georg Pauwen]

Hello,

so the subnets overlap...are duplicate IP addresses in use as well ? If not, you could just use static host routes, as these would be more specific and override everything else.

If so, some sort of NAT could indeed be an option. I will need to lab this...

[abhayjoshi07]

Yes, the duplicate IPs are in use as well. This is just one sample subnet that I have mentioned and there are few other overlapping subnets that require a solution.