Connectivity Guide

Static route leaking
Route leaking enables routes that are congured in a default or non-default VRF instance to be made available to another VRF instance.
You can leak routes from a source VRF instance to a destination VRF instance.
The routes need to be leaked in both source as well as destination VRFs in order to achieve end-to-end trac ow.
If there are any connected routes in the same subnet as statically leaked routes. then the connected routes take precedence.
In static route leaking, DHCP functionality does not work for overlapping subnets. For example, if two interfaces on dierent VRFs are on
the same subnet and are congured with the same DHCP server, then only one of those interface get an IP address. This is because the
client requests from these interfaces have the same MAC and subnet addresses. The server does not have any unique parameter to
dierentiate that the request is from two dierent clients.
Limitations
• In VLT scenarios, the resolved ARP entry for the leaked route is not synced between the VLT peers. The ARP entry resolved in the
source VRF is programmed into the leaked VRF when the leaked route conguration is active.
• During downgrade from 10.4.2, the leaked route conguration is restored. However, the routes remain inactive in the destination VRF
instance.
• During downgrade from 10.4.2, the update-source-if command is not restored.
Conguring static route leaking
To congure static route leaking:
1 Enter the interface in the source VRF instance that contains the static routes that you want to leak.
interface interface-name
CONFIGURATION Mode
2 In INTERFACE CONFIGURATION Mode, assign the interface to the source VRF instance.
ip vrf forwarding vrf1
INTERFACE CONFIGURATION Mode
3 Assign an IP address to the interface.
ip address ip-address
VRF CONFIGURATION Mode
4 Enter the interface of the VRF instance to which you want to leak the static routes.
interface interface-name
CONFIGURATION Mode
5 In INTERFACE CONFIGURATION Mode, assign the interface to the destination VRF instance.
ip vrf forwarding vrf2
INTERFACE CONFIGURATION Mode
6 Congure the static route that you want to leak on the destination VRF instance.
ip route vrf dest-vrf-name route nexthop-interface
7 Congure the static route that you have congured earlier in the source VRF instance to be available in the destination VRF instance
also.
396
Layer 3