VRF

What it does

• Overlapping IP Addresses:

  This allows different networks or customers to use the same IP address ranges without interfering with each other. 

• Isolation:

  Each VRF (Virtual Routing and Forwarding) instance is isolated, meaning traffic destined for one VRF cannot reach devices in another VRF. 

• Simplifies Management:

  VRF Lite can simplify network management by allowing for the logical segmentation of a network. 

• No MPLS Required:

  Unlike full VRF implementations, VRF Lite does not require MPLS (Multiprotocol Label Switching) or MP-BGP (Multiprotocol Border Gateway Protocol). 

• Creates Virtual Routing Tables:

  VRF Lite essentially carves up a single physical router into multiple logical routers, each with its own routing table. 

How it works:

• Interfaces: Each interface on the router is assigned to a specific VRF. 

• Routing Tables: Each VRF has its own routing table, independent of other VRFs. 

• Forwarding: Traffic is forwarded based on the routing table associated with the VRF to which the incoming interface belongs. 

Use Cases:

• Multi-Tenant Environments:

  Service providers can use VRF Lite to isolate traffic from different customers on the same physical infrastructure. 

• Network Segmentation:

  VRF Lite can be used to logically separate different departments or functions within an organization. 

• Guest Networks:

  It can be used to isolate guest Wi-Fi networks from the corporate network. 

• Merging Networks:

  VRF Lite can help when merging networks with overlapping IP address spaces, avoiding the need for extensive re-addressing. 

Adding Ports to a VRF

• Click Switching on the left menu, then click on Routing & DHCP. 

• Select the interface you would like to edit and add to a pre-configured VRF.  

• In the VRF drop down box, select the VRF you would like assign the selected interface to.

• Click Save changes.

Removing Ports from a VRF 

• Click Switching on the left menu, then click on Routing & DHCP.  

• Select the interface you would like to edit and remove from a VRF.   

• In the VRF drop down box, select the default VRF to move the interface back to the default VRF. 

• Click Save changes.

Deleting a VRF 

• Click Organization on the left menu, then click on VRFs.  

• Click the VRF you would like to delete to highlight it. 

• Click Delete. 

Route Leaking

Route leaking between Global Routing Table and Virtual Routing and Forwarding (VRF) table is facilitated with the use of static routes. Either method provides the next-hop IP address.  At times, only a single uplink is available to peer to an upstream appliance, which in this instance, the ability to leak a route from the default routing table can be used to ensure traffic can enter/leave a VRF.  

• Click Add static routes or the pencil to edit an existing static route.

• Click the Enabled box next to Global as depicted in the screen shot below.  

• Click Save.

Adding OSPF to a VRF

• Click Switching on the left menu, then click OSPF Routing.  
• Next to VRFs, click the VRF you would like to enable OSPF routing in.
• Click Enabled.
• Enter in the Hello timer and dead timer values if different than the default.  
• Click Add an area to configure the area.
  • Enter the area ID, Name, and select the area Type. 
• Click Switching on the left menu, then click on Routing & DHCP.
• Navigate to the interface you are adding the OSPF area to and click the pencil to edit.
• Under OSPF settings click on the drop down arrow next to Area and select the appropriate area.
• Configure the Cost if different than the default value of 1.
• Select if the interface will be Passive or not.
• Select the Network type*.
• Click Save changes.