Contents
How does VRF routing work?
Virtual routing and forwarding (VRF) IP technology allows users to configure multiple routing table instances to simultaneously co-exist within the same router. Overlapping IP addresses can be used without conflicting because the multiple routing instances are independent, and can select different outgoing interfaces.
What is VRF Cisco router?
Virtual Routing and Forwarding or VRF is a technology that supports multiple routing instance inside a single router (or layer-3 switch). This means a single router can have multiple separated routing table and each one is completely independent. Cisco IOS router supports VRF by default.
What is the main function of VRF-Lite?
VRF-lite is a feature that enables a service provider to support two or more VPNs, where IP addresses can be overlapped among the VPNs. VRF-lite uses input interfaces to distinguish routes for different VPNs and forms virtual packet-forwarding tables by associating one or more Layer 3 interfaces with each VRF.
How is VRF used in a network router?
The VRF’s full form in networking is Virtual Routing and Forwarding. A network router does a lookup in the routing table and forwards the packet towards the next hop. The routing table is global and applicable to all network traffic coming in.
What is telnet / SSH access to device with VRF’s?
This document describes the configuration of device access with Telnet or Secure Shell (SSH) across a Virtual Routing and Forwarding (VRF). In IP-based computer networks, VRF is a technology that allows multiple instances of a routing table to co-exist within the same router at the same time.
Can a host access a host in the same VRF?
If we have VRF, a host can access hosts in the same VRF. Using VRF, an ISP can provide isolation of IP traffic between distance hosts. The ISP will configure VRF on each router between the path. These are similar to the normal routing tables associated with an interface.
Are there any physical interfaces assigned to a VRF?
The physical trunk interfaces F0/13 and F0/16 are not assigned to a VRF, because they are not routed interfaces. VRF configuration is only relevant at layer three. We can use show ip vrf to examine the VRFs and their assigned interfaces: