User's Manual
Table Of Contents
- Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
- Contents
- Preface
- New and Changed Information for this Release
- Overview
- Configuring Ethernet Interfaces
- Information About Ethernet Interfaces
- Configuring Ethernet Interfaces
- Configuring the UDLD Mode
- Changing an Interface Port Mode
- Configuring Interface Speed
- Disabling Link Negotiation
- Configuring the CDP Characteristics
- Enabling or Disabling CDP
- Enabling the Error-Disabled Detection
- Enabling the Error-Disabled Recovery
- Configuring the Error-Disabled Recovery Interval
- Configuring the Debounce Timer
- Configuring the Description Parameter
- Disabling and Restarting Ethernet Interfaces
- Displaying Interface Information
- Displaying Input Packet Discard Information
- Default Physical Ethernet Settings
- Configuring VLANs
- Configuring Private VLANs
- Information About Private VLANs
- Guidelines and Limitations for Private VLANs
- Configuring a Private VLAN
- Enabling Private VLANs
- Configuring a VLAN as a Private VLAN
- Associating Secondary VLANs with a Primary Private VLAN
- Configuring an Interface as a Private VLAN Host Port
- Configuring an Interface as a Private VLAN Promiscuous Port
- Configuring a Promiscuous Trunk Port
- Configuring an Isolated Trunk Port
- Configuring the Allowed VLANs for PVLAN Trunking Ports
- Configuring Native 802.1Q VLANs on Private VLANs
- Verifying the Private VLAN Configuration
- Configuring Access and Trunk Interfaces
- Configuring Switching Modes
- Configuring Rapid PVST+
- Information About Rapid PVST+
- Understanding STP
- Understanding Rapid PVST+
- Rapid PVST+ and IEEE 802.1Q Trunks
- Rapid PVST+ Interoperation with Legacy 802.1D STP
- Rapid PVST+ Interoperation with 802.1s MST
- Configuring Rapid PVST+
- Enabling Rapid PVST+
- Enabling Rapid PVST+ per VLAN
- Configuring the Root Bridge ID
- Configuring a Secondary Root Bridge
- Configuring the Rapid PVST+ Port Priority
- Configuring the Rapid PVST+ Pathcost Method and Port Cost
- Configuring the Rapid PVST+ Bridge Priority of a VLAN
- Configuring the Rapid PVST+ Hello Time for a VLAN
- Configuring the Rapid PVST+ Forward Delay Time for a VLAN
- Configuring the Rapid PVST+ Maximum Age Time for a VLAN
- Specifying the Link Type
- Restarting the Protocol
- Verifying Rapid PVST+ Configurations
- Information About Rapid PVST+
- Configuring Multiple Spanning Tree
- Information About MST
- Configuring MST
- MST Configuration Guidelines
- Enabling MST
- Entering MST Configuration Mode
- Specifying the MST Name
- Specifying the MST Configuration Revision Number
- Specifying the Configuration on an MST Region
- Mapping and Unmapping VLANs to MST Instances
- Mapping Secondary VLANs to Same MSTI as Primary VLANs for Private VLANs
- Configuring the Root Bridge
- Configuring a Secondary Root Bridge
- Configuring the Port Priority
- Configuring the Port Cost
- Configuring the Switch Priority
- Configuring the Hello Time
- Configuring the Forwarding-Delay Time
- Configuring the Maximum-Aging Time
- Configuring the Maximum-Hop Count
- Configuring PVST Simulation Globally
- Configuring PVST Simulation Per Port
- Specifying the Link Type
- Restarting the Protocol
- Verifying MST Configurations
- Configuring STP Extensions
- About STP Extensions
- Information About STP Extensions
- Configuring STP Extensions
- STP Extensions Configuration Guidelines
- Configuring Spanning Tree Port Types Globally
- Configuring Spanning Tree Edge Ports on Specified Interfaces
- Configuring Spanning Tree Network Ports on Specified Interfaces
- Enabling BPDU Guard Globally
- Enabling BPDU Guard on Specified Interfaces
- Enabling BPDU Filtering Globally
- Enabling BPDU Filtering on Specified Interfaces
- Enabling Loop Guard Globally
- Enabling Loop Guard or Root Guard on Specified Interfaces
- Verifying STP Extension Configuration
- About STP Extensions
- Configuring LLDP
- Configuring the MAC Address Table
- Configuring IGMP Snooping
- Configuring Traffic Storm Control
- INDEX
put into a root-inconsistent (blocked) state. After the port stops send superior BPDUs, the port is unblocked
again. Through STP, the port moves to the forwarding state. Recovery is automatic.
Root Guard enabled on an interface applies this functionality to all VLANs to which that interface belongs.
You can use Root Guard to enforce the root bridge placement in the network. Root Guard ensures that the
port on which Root Guard is enabled is the designated port. Normally, root bridge ports are all designated
ports, unless two or more of the ports of the root bridge are connected. If the bridge receives superior BPDUs
on a Root Guard-enabled port, the bridge moves this port to a root-inconsistent STP state. In this way, Root
Guard enforces the position of the root bridge.
You cannot configure Root Guard globally.
You can enable Root Guard on all spanning tree port types: normal, edge, and network ports.Note
Configuring STP Extensions
STP Extensions Configuration Guidelines
When configuring STP extensions, follow these guidelines:
•
Configure all access and trunk ports connected to hosts as edge ports.
•
Bridge Assurance runs only on point-to-point spanning tree network ports. You must configure each
side of the link for this feature.
•
Loop Guard does not run on spanning tree edge ports.
•
Enabling Loop Guard on ports that are not connected to a point-to-point link will not work.
•
You cannot enable Loop Guard if Root Guard is enabled.
Configuring Spanning Tree Port Types Globally
The spanning tree port type designation depends on the type of device the port is connected to, as follows:
• Edge—Edge ports are connected to hosts and can be either an access port or a trunk port.
• Network—Network ports are connected only to switches or bridges.
• Normal—Normal ports are neither edge ports nor network ports; they are normal spanning tree ports.
These ports can be connected to any type of device.
You can configure the port type either globally or per interface. By default, the spanning tree port type is
normal.
Before You Begin
Ensure that STP is configured.
Ensure that you are configuring the ports correctly for the type of device to which the interface is connected.
Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
OL-26590-01 117
Configuring STP Extensions
Configuring STP Extensions