Interface FastEthernet8 <- wan port facing the internet for guest traffic Interface Vlan10 <- SVI interface for Intranet trafficĭescription Intranet <- interface is attached to the Intranet VRF Ip vrf forwarding Intranet <- interface is attached to the Intranet VRF Interface GigabitEthernet0 <-– wan port facing the internet for Intranet traffic Step 2 : Configure VLANs and interfaces and include them in the VRF instances
The company security team demanded that the Wi-Fi connection must be totally separated from the local intranet network, so that guests don’t have access to the local network. We have a Cisco 891 border router with an Intranet connection for employees’ computers and company servers and also we need to offer internet connectivity for a Wi-Fi connection to allow guests to connect to the internet.
To demonstrate how to use this feature lets see the following simplified scenario: Network Scenario using Cisco 891 and VRF LiteĬonsider the scenario depicted on the diagram above. Each routing table (VRF instance) is isolated from the other VRF instances. With VRF Lite, you can have separate routing tables on the same physical router device. Now, although VRFs and MPLS are usually configured on high-end ISP routers, you can still use this feature on some smaller Cisco ISR routers in a simplified manner called VRF Lite and have the same advantages. If you want to read about this technology, one good book to start with is MPLS Fundamentals wrote by Luc De Ghein. They are discussed in the chapters needed for your CCIE R&S certification.
Also, from what I know, MPLS and VRFs are not examined at the CCNA or CCNP R&S level. If you don’t work in an ISP environment you will not encounter this technology very often. VRF (Virtual Routing and Forwarding) is traditionally associated with IP MPLS technology whereby an ISP creates Layer3 (or Layer2) VPNs for customers using VRF.Ĭonsider a VRF as a separate routing instance (and separate routing table) on the same network device holding the IP routes for each customer which are isolated from the other customers.Įach VRF is like a separate virtual router with its own routing table on the same physical router. VRFs employ essentially the same concept as VLANs and Trunking, but at Layer 3. In this tutorial, we will discuss traffic isolation at Layer3 level using VRF Lite on Cisco routers. In the previous post, we have discussed about isolating traffic using the private VLAN feature at Layer2 level.