54. VIRTUALIZATION (VRF): PART 3
INTRO TO VRF
Click to enlarge
- VIRTUAL ROUTING AND FORWARDING (VRF) is used to DIVIDE a SINGLE ROUTER into MULTIPLE VIRTUAL ROUTERS
- Similar to how VLANs are used to divide a SINGLE SWITCH (LAN) into MULTIPLE VIRTUAL SWITCHES (VLANs)
- It does this by allowing a ROUTER to build MULTIPLE SEPARATE ROUTING TABLES
- INTERFACES (LAYER 3 only) and ROUTERS are configured to be in a specific VRF (aka VRF INSTANCE)
- ROUTER INTERFACES, SVIs and ROUTED PORTS on MULTILAYER SWITCHES can be configured in a VRF
- TRAFFIC in one VRF cannot be forwarded out of an INTERFACE in another VRF
- As an exception, VRF LEAKING can be configured to allow traffic to pass BETWEEN VRFs
- VRF is commonly used to facilitate MPLS (Multiple Protocol Label Switching)
- The kind of VRF we are talking about is VRF-Lite (VRF without MPLS)
- VRF is commonly used by SERVICE PROVIDERS to allow ONE DEVICE to carry traffic from MULTIPLE CUSTOMERS
- Each CUSTOMER’S TRAFFIC is isolated from the OUTSIDE
- CUSTOMER IP ADDRESSES can overlap without issue
VRF CONFIGURATION
Click to enlarge
Creation and Configuration of VRFs
Click to enlarge
How to show ip route for VRFs
Click to enlarge
ping other VRFs
Click to enlarge