Este escenario es un poco complejo pero vamos a explicarlo. Imaginemos que tenemos 2 routers (R1 y R2) que brindan transporte a R3 y R4. Para que ambos routers se comuniquen deben hacerlo a traves del protocolo de enrrutamiento OSPF. Pero hay un problema, R3 esta configurado en la interfaz que habla con R1 en el VRF okidoki. Y de igual modo R1 recibe el trafico de R3 en el VRF good para posteriormente pasar el trafico en el mismo VRF a R4.
El problema esta en que si R3 esta en un VRF y configuramos L3VPN normal con OSPF, por default R3 no va a recibir las rutas de okidoki porque el trafico esta siendo recibido en R3 en un VRF y el bloqueado porque el down-bit y domain-tag estan filtrados.
Por esa razon, la forma de resolver esto es de 2 maneras:
El problema esta en que si R3 esta en un VRF y configuramos L3VPN normal con OSPF, por default R3 no va a recibir las rutas de okidoki porque el trafico esta siendo recibido en R3 en un VRF y el bloqueado porque el down-bit y domain-tag estan filtrados.
Por esa razon, la forma de resolver esto es de 2 maneras:
- Sham-Link
- Capability vrf-lite
proceso de configuracion de OSPF capability VRF-Lite.
Configuración Router R1
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip source-route
ip vrf good
rd 28118:1
route-target export 28118:1
route-target import 28118:1
!
!
!
!
!
no ip domain lookup
ip cef
no ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 10.10.10.1 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
ip vrf forwarding good
ip address 10.0.0.13 255.255.255.255
!
interface Ethernet0/0
no ip address
shutdown
duplex auto
!
interface GigabitEthernet0/0
ip address 10.0.0.5 255.255.255.252
ip ospf 1 area 0
media-type gbic
speed 1000
duplex full
negotiation auto
mpls ip
!
interface GigabitEthernet1/0
ip vrf forwarding good
ip address 10.0.0.1 255.255.255.252
ip ospf 100 area 0
negotiation auto
!
router ospf 100 vrf good
log-adjacency-changes
area 0 sham-link 10.0.0.13 10.0.0.14
redistribute bgp 28118 subnets
network 10.0.0.0 0.0.0.3 area 0
!
router ospf 1
log-adjacency-changes
network 10.0.0.4 0.0.0.3 area 0
!
router bgp 28118
no synchronization
bgp log-neighbor-changes
neighbor 10.10.10.2 remote-as 28118
neighbor 10.10.10.2 description To_R2
neighbor 10.10.10.2 update-source Loopback0
no auto-summary
!
address-family vpnv4
neighbor 10.10.10.2 activate
neighbor 10.10.10.2 send-community both
exit-address-family
!
address-family ipv4 vrf good
no synchronization
redistribute connected
redistribute ospf 100 vrf good
exit-address-family
!
!
!
no ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
line con 0
stopbits 1
line aux 0
line vty 0 4
!
end
Configuración Router R2
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip source-route
ip vrf good
rd 28118:1
route-target export 28118:1
route-target import 28118:1
!
!
!
!
!
ip cef
no ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 10.10.10.2 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
ip vrf forwarding good
ip address 10.0.0.14 255.255.255.255
!
interface Ethernet0/0
no ip address
shutdown
duplex auto
!
interface GigabitEthernet0/0
ip address 10.0.0.6 255.255.255.252
ip ospf 1 area 0
media-type gbic
speed 1000
duplex full
negotiation auto
mpls ip
!
interface GigabitEthernet1/0
ip vrf forwarding good
ip address 10.0.0.9 255.255.255.252
ip ospf 100 area 0
negotiation auto
!
router ospf 100 vrf good
log-adjacency-changes
area 0 sham-link 10.0.0.14 10.0.0.13
redistribute bgp 28118 subnets
network 10.0.0.8 0.0.0.3 area 0
!
router ospf 1
log-adjacency-changes
!
router bgp 28118
no synchronization
bgp log-neighbor-changes
neighbor 10.10.10.1 remote-as 28118
neighbor 10.10.10.1 description To_R1
neighbor 10.10.10.1 update-source Loopback0
no auto-summary
!
address-family vpnv4
neighbor 10.10.10.1 activate
neighbor 10.10.10.1 send-community both
exit-address-family
!
address-family ipv4 vrf good
no synchronization
redistribute connected
redistribute ospf 100 vrf good
exit-address-family
!
!
!
no ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
line con 0
stopbits 1
line aux 0
line vty 0 4
!
end
Configuración Router R3
version 12.2Configuración Router R4
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R3
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip source-route
ip vrf doki
rd 11:11
route-target export 9:9
route-target import 9:9
!
ip vrf oki
rd 10:10
route-target export 10:10
route-target import 10:10
!
ip vrf okidoki
rd 9:9
route-target export 9:9
route-target import 9:9
!
!
!
!
!
no ip domain lookup
ip cef
no ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip vrf forwarding oki
ip address 172.16.0.1 255.255.255.0
!
interface Loopback1
ip vrf forwarding doki
ip address 172.17.0.1 255.255.255.0
!
interface Loopback2
ip address 172.18.0.1 255.255.255.255
!
interface Loopback3
ip address 172.19.0.1 255.255.255.255
!
interface Ethernet0/0
no ip address
shutdown
duplex auto
!
interface GigabitEthernet0/0
ip vrf forwarding okidoki
ip address 10.0.0.2 255.255.255.252
ip ospf 100 area 0
media-type gbic
speed 1000
duplex full
negotiation auto
!
router ospf 100 vrf okidoki
log-adjacency-changes
network 10.0.0.0 0.0.0.3 area 0
!
!
!
no ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
line con 0
stopbits 1
line aux 0
line vty 0 4
!
end
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R4
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip source-route
ip vrf okidoki
rd 9:9
route-target export 9:9
route-target import 9:9
!
!
!
!
!
ip cef
no ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
interface Ethernet0/0
no ip address
shutdown
duplex auto
!
interface GigabitEthernet0/0
ip vrf forwarding okidoki
ip address 10.0.0.10 255.255.255.252
ip ospf 100 area 0
media-type gbic
speed 1000
duplex full
negotiation auto
!
router ospf 100 vrf okidoki
log-adjacency-changes
network 10.0.0.8 0.0.0.3 area 0
!
!
!
no ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
line con 0
stopbits 1
line aux 0
line vty 0 4
!
end
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