Manualshelf

Users Guide

ManualsBrandsDell ManualsAccess PlatformsW-Series Controller AOS
241242243244245246247248249250
Table Of Contents
250| BranchController Config for Controllers Dell Networking W-Series ArubaOS 6.5.x| User Guide
In most deployments, edge ports are access ports. However, in this scenario there are no restrictions in
enabling the PortFast feature. The mode of the port changes from PortFast to non-PortFast when the port
receives a STP BPDU. To re-enable this feature on a port, run the shut command followed by a no-shut
command at the interface/port level.
Configuring PortFast on a non-edge port can cause instability to the STP topology.
BPDU Guard
BPDU Guard feature protects the port from receiving STP BPDUs, however the port can transmit STP BPDUs.
When a STP BPDU is received on a BPDU Guard enabled port, the port is shutdown and the state of the port
changes to ErrDis (Error-Disable) state. The port remains in the ErrDis state until the port status is manually
changed by using the configuration command shut followed by a no-shut applied on the interface. In most
deployments, BPDU Guard feature is configured over the PortFast enabled STP ports, but in this
implementation the BPDU Guard feature can be enabled on any of the STP ports, with or without PortFast
feature being enabled on these ports.
It is recommended not to enable the BPDUGuard feature on a trunk port that forms the STP topology.
Scenarios Supported on PortFast and BPDU Guard
PortFast and BPDU Guard features are applied at the port/interface level. These features can also be applied in
the following scenarios:
l RSTP and PVST modes
l Access and Trunk ports
l Physical and Logical ports
The PortFast and BPDU Guard features can be applied either independently or together.
In the global RSTPmode there is only one RSTP instance running in the entire controller. If the port that is
enabled with PortFast and BPDU Guard receives any STP BPDU it will effect all the ports, as the global RSTP
runs on a port basis.
In the PVST mode there can be multiple instances of RSTP running as they are based on per VLAN. Though it is
based on per VLAN, it will still behave in the same way as it does in the global RSTP mode. For example, if there
are five VLANs and each VLAN has a separate RSTP instance running, then any STP BPDU received on any of
these five ports effects all ports.
If an STP BPDU is received from any one of the five RSTP instances running, the port that is enabled with BPDU
Guard shuts down and goes to ErrDis state. In other words both PortFast and BPDU Guard features are
applied on a port basis for both global RSTP and PVST modes, even though the PVST runs on a per VLAN basis.
Enabling PortFast and BPDU Guard on a Port
The following section guides you to enable the PortFast and BPDU Guard features on a port.
In the Web UI
Follow the steps below to enable PortFast and BPDU Guard features on a port using the WebUI:
1. Navigate to Configuration>Branch>Smart Config and select the Networking tab.
2. In the Ports table, click the port number for which you want to enable PortFast and BPDU Guard.
3. Click Edit.
4. Select the PortFast and BPDU Guard checkbox.