Last Updated on August 3, 2021 by Admin 2
Which of the following is true of the default VRF on a Cisco router?
- It includes only the mgmt 0 interface.
- No routing protocols are allowed to run there.
- It is similar to a router’s global routing table.
- It is used only for management.
A Cisco router’s default virtual routing and forwarding (VRF) instance is similar to a router’s global routing table. The default VRF includes all Layer 3 interfaces until you assign those interfaces to another VRF. Similarly, the default VRF runs any routing protocols that are configured unless those routing protocols are assigned to another VRF. All show and exec commands that are issued in the default VRF apply to the default routing context.
VRFs are used to logically separate Open Systems Interconnection (OSI) networking model Layer 3 networks. Therefore, it is possible to have overlapping Internet Protocol version 4 (IPv4) or Internet Protocol version 6 (IPv6) addresses in environments that contain multiple tenants. However, an interface that has been assigned to a given VRF cannot be simultaneously assigned to another VRF. The address space, routing process, and forwarding table that are used within a VRF are local to that VRF. By default, a Cisco router is configured with two VRFs: the management VRF and the default VRF.
The management VRF, not the default VRF, is used only for management. No routing protocols are allowed to run in the management VRF. All routing is static. The management VRF includes only the mgmt 0 interface, which cannot be assigned to any other VRF. However, the mgmt 0 interface is shared among virtual device contexts (VDCs).