Executive Summary:

At a managed service provider, we were tasked with segregating network traffic for different clients while using a shared infrastructure. We designed a network using Virtual Routing and Forwarding (VRF) instances to create separate routing tables for each client, ensuring proper routing and isolation. We configured VRF-aware routing protocols, such as OSPF and BGP, to maintain client-specific routing tables. The result was a secure, efficient, and scalable network that met client requirements.

Introduction:

In a shared infrastructure environment, isolating traffic for different clients or departments is crucial for maintaining security and privacy. Virtual Routing and Forwarding (VRF) instances allow network administrators to create multiple, isolated routing tables on a single router, segregating traffic and ensuring proper routing between different entities. In this scenario, we designed a network using VRFs to segregate traffic for different clients.

Implementation Steps:

1. Creating VRF instances: For each client, we created a VRF instance on the routers responsible for their traffic. The configuration on Cisco routers was as follows:

ip vrf CLIENT-A
rd 1:1
ip vrf CLIENT-B
rd 2:1

2. Assigning interfaces to VRFs: We assigned the appropriate router interfaces to their corresponding VRFs:

interface GigabitEthernet0/0
ip vrf forwarding CLIENT-A
ip address 192.168.1.1 255.255.255.0

interface GigabitEthernet0/1
ip vrf forwarding CLIENT-B
ip address 192.168.2.1 255.255.255.0

3. Configuring VRF-aware OSPF: For clients using OSPF as their routing protocol, we configured VRF-aware OSPF instances:

router ospf 1 vrf CLIENT-A
network 192.168.1.0 0.0.0.255 area 0
redistribute bgp 65000 metric-type 1

router ospf 2 vrf CLIENT-B
network 192.168.2.0 0.0.0.255 area 0
redistribute bgp 65000 metric-type 1

4. Configuring VRF-aware BGP: For clients using BGP as their routing protocol, we configured VRF-aware BGP instances:

router bgp 65000
address-family ipv4 vrf CLIENT-A
neighbor 192.168.1.2 remote-as 65001
neighbor 192.168.1.2 activate
redistribute ospf 1

address-family ipv4 vrf CLIENT-B
neighbor 192.168.2.2 remote-as 65002
neighbor 192.168.2.2 activate
redistribute ospf 2

5. Verifying proper routing and isolation: We verified the proper operation of VRFs and routing protocols by checking the routing tables for each VRF:

show ip route vrf CLIENT-A
show ip route vrf CLIENT-B

Outcome:

By implementing VRFs and configuring VRF-aware routing protocols, we were able to segregate traffic for different clients on a shared infrastructure. This design ensured proper routing and isolation between clients, providing a secure and efficient network. The use of VRFs also allowed for scalability, as additional clients or departments could be easily added to the network without affecting existing configurations. This network design met the client requirements and provided a robust solution for traffic segregation on shared infrastructure.