Virtualization - Cisco Nexus 7000 Series Configuration Manual

Virtualization

• Loop Guard—Loop guard helps prevent bridging loops that could occur because of a unidirectional link
• Root Guard—The root guard feature prevents a port from becoming root port or blocked port. If a port
Virtualization
Cisco NX-OS devices introduce support for multiple virtual device contexts (VDCs) on a single switching
device. Each VDC is treated as a standalone device with specific resources, such as physical interfaces,
allocated to each VDC by the network admin role. An administrator is assigned to each VDC and that
administrator has a limited view of the system within that specific VDC. Faults are also isolated to within the
specific VDC.
This VDC concept applies to all features on Cisco NX-OS, including all Layer 2 switching features.
All processes work independently in each VDC. You can reuse the process identification numbers in different
VDCs. This figure shows how to reuse the VLAN 100 identifier in each separate VDC.
Figure 1: VDCs with Layer 2 Services
Each VDC acts as a standalone device with Layer 2 services available. VDCs allow you to share a physical
device among several logical functions. You can provision and assign entirely separate Layer 2 resources to
individual VDCs.
You can configure several VDCs, and each VDC is a group of physical device resources. You assign resources
and user roles for each VDC. VDCs allows flexible resources as well as enhanced fault isolation.
Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x
6
failure on a point-to-point link.
configured for root guard receives a superior BPDU, the port immediately goes to the root-inconsistent
(blocked) state.
Overview