Dell S4048T, Руководство по настройке

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interface TenGigabitEthernet 1/10
ip vrf forwarding VRF2
ip address 140.0.0.1/24
ip route vrf VRF1 20.0.0.0/16 140.0.0.2 vrf VRF2
ip route vrf VRF2 40.0.0.0/16 120.0.0.2 vrf VRF1
Dynamic Route Leaking
Route Leaking is a powerful feature that enables communication between isolated (virtual) routing domains
by segregating and sharing a set of services such as VOIP, Video, and so on that are available on one routing
domain with other virtual domains. Inter-VRF Route Leaking enables a VRF to leak or export routes that are
present in its RTM to one or more VRFs.
Dynamic Route Leaking enables a source VRF to share both its connected routes as well as dynamically learnt
routes from various protocols, such as ISIS, OSPF, BGP, and so on, with other default or non-default VRFs.
You can also leak global routes to be made available to VRFs. As the global RTM usually contains a large pool
of routes, when the destination VRF imports global routes, these routes will be duplicated into the VRF's RTM.
As a result, it is mandatory to use route-maps to filter out leaked routes while sharing global routes with VRFs.
Configuring Route Leaking without Filtering
Criteria
You can use the
ip route-export tag
command to export all the IPv4 routes corresponding to a source
VRF. For leaking IPv6 routes, use the
ipv6 route-export tag
command. This action exposes source VRF's
routes (IPv4 or IPv6 depending on the command that you use) to various other VRFs. The destinations or
target VRFs then import these IPv4 or IPv6 routes using the
ip route-import tag
or the
ipv6 route-
import tag
command respectively.
NOTE: In Dell Networking OS, you can configure at most one route-export per VRF as only one set of
routes can be exposed for leaking. However, you can configure multiple route-import targets because a
VRF can accept routes from multiple VRFs.
After the target VRF learns routes that are leaked by the source VRF, the source VRF in turn can leak the
export target corresponding to the destination VRFs that have imported its routes. The source VRF learns the
export target corresponding to the destinations VRF using the
ip route-import tag
or
ipv6 route-
import tag
command. This mechanism enables reverse communication between destination VRF and the
source VRF.
If the target VRF contains the same prefix (either sourced or Leaked route from some other VRF), then the
Leak for that particular prefix will fail and an error-log will be thrown. Manual intervention is required to clear
the unneeded prefixes. The source route will take priority over the leaked route and the leaked route is
deleted.
Consider a scenario where you have created four VRF tables VRF-red, VRF-blue, VRF-Green, and VRF-shared.
The VRF-shared table belongs to a particular service that should be made available only to VRF-Red and VRF-
Blue but not VRF-Green. For this purpose, routes corresponding VRF-Shared routes are leaked to only VRF-
Red and VRF-Blue. And for reply, routes corresponding to VRF-Red and VRF-Blue are leaked to VRF-Shared.
Virtual Routing and Forwarding (VRF) 1202