Inter-VRF-Lite routing (1/7)

Customer VRFs & Global routing instance

- R1 separates Customer traffic with different routing instances “vhost4″, “vhost5″ and a global routing instance for common site traffic.

- Customers (40.0.0.0/24 and 50.0.0.0/24) communicate ONLY with the common site.

Picture 1-1: topology

Inter-VRF communications depends on static routing from one VRF to other VRF outbound interfaces

ip vrf vhost4

rd 400:400

route-target export 400:400

route-target import 400:400

!

ip vrf vhost5

rd 500:500

route-target export 500:500

route-target import 500:500

R1 configuration

interface Serial1/0.104 point-to-point

ip vrf forwarding vhost4

description VRF vhost4 sub-interface

ip address 155.1.0.14 255.255.255.0

frame-relay interface-dlci 104

!

interface Serial1/0.105 point-to-point

description VRF vhost5 sub-interface

ip vrf forwarding vhost5

ip address 155.1.0.15 255.255.255.0

frame-relay interface-dlci 105

!

interface FastEthernet2/0

description Interface belonging to global routing instance

ip address 172.1.1.1 255.255.255.0

Static inter-vrf (route leaking of VRF prefixes to Global RIB)

ip route 40.0.0.0 255.255.255.0 Serial1/0.104

ip route 50.0.0.0 255.255.255.0 Serial1/0.105

VRF vhost5

ip route vrf vhost5 50.0.0.0 255.255.255.0 Serial1/0.105 155.1.0.5

static inter-vrf (route leaking of Global RIB prefixes to VRF RIB)

ip route vrf vhost5 172.1.1.7 255.255.255.255 FastEthernet2/0 172.1.1.7 global

VRF vhost4

ip route vrf vhost4 40.0.0.0 255.255.255.0 Serial1/0.104 155.1.0.4

Static inter-vrf (route leaking of Global RIB prefixes to VRF RIB)

ip route vrf vhost4 172.1.1.7 255.255.255.255 FastEthernet2/0 172.1.1.7 global

Global routing table

R1#sh ip route

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets

C 1.1.1.1 is directly connected, Loopback1

50.0.0.0/24 is subnetted, 1 subnets

S 50.0.0.0 is directly connected, Serial1/0.105

172.1.0.0/24 is subnetted, 1 subnets

C 172.1.1.0 is directly connected, FastEthernet2/0

40.0.0.0/24 is subnetted, 1 subnets

S 40.0.0.0 is directly connected, Serial1/0.104

R1#

VRF vhost4 RIB

R1#sh ip route vrf vhost4

Routing Table: vhost4

Gateway of last resort is not set

155.1.0.0/24 is subnetted, 1 subnets

C 155.1.0.0 is directly connected, Serial1/0.104

172.1.0.0/32 is subnetted, 1 subnets

S 172.1.1.7 [1/0] via 172.1.1.7, FastEthernet2/0

40.0.0.0/24 is subnetted, 1 subnets

S 40.0.0.0 [1/0] via 155.1.0.4, Serial1/0.104

R1#

VRF vhost5 RIB

R1#sh ip route vrf vhost4

Routing Table: vhost5

Gateway of last resort is not set

50.0.0.0/24 is subnetted, 1 subnets

S 50.0.0.0 [1/0] via 155.1.0.5, Serial1/0.105

155.1.0.0/24 is subnetted, 1 subnets

C 155.1.0.0 is directly connected, Serial1/0.105

172.1.0.0/32 is subnetted, 1 subnets

S 172.1.1.7 [1/0] via 172.1.1.7, FastEthernet2/0

R1#

Testing From Customer A

vhost#trace vrf vhost5 172.1.1.7

Type escape sequence to abort.

Tracing the route to 172.1.1.7

1 50.0.0.5 88 msec 16 msec 4 msec

2 155.1.0.15 56 msec 52 msec 20 msec

3 172.1.1.7 68 msec * 124 msec

vhost#

Testing From Customer B

vhost#trace vrf vhost4 172.1.1.7

Type escape sequence to abort.

Tracing the route to 172.1.1.7

1 40.0.0.4 68 msec 20 msec 48 msec

2 155.1.0.14 52 msec 28 msec 16 msec

3 172.1.1.7 60 msec * 132 msec

vhost#

Testing from Common site

vhost#trace vrf vhost7 50.0.0.1

Type escape sequence to abort.

Tracing the route to 50.0.0.1

1 172.1.1.1 80 msec 44 msec 4 msec

2 155.1.0.5 96 msec 36 msec 16 msec

3 50.0.0.1 40 msec * 108 msec

vhost#trace vrf vhost7 40.0.0.1

Type escape sequence to abort.

Tracing the route to 40.0.0.1

1 172.1.1.1 92 msec 64 msec 4 msec

2 155.1.0.4 96 msec 48 msec 12 msec

3 40.0.0.1 64 msec * 96 msec

vhost#

Back to main article

About these ads