Rockwell Automation 1783-BMxxx Stratix 5700 Ethernet Managed Switches User Manual - Manual (Page 150)

150 Rockwell Automation Publication 1783-UM004E-EN-P - June 2014
Chapter 4 Manage the Switch via the Device Manager Web Interface
PortFast Settings
To enable PortFast and related features, click the PortFast tab. On the PortFast
tab, you can change the way that STP is implemented on individual ports.
PortFast features are typically enabled only on access ports, which connect to
devices such as personal computers, access points, and servers that are not
expected to send bridge protocol data units (BPDUs). These features are typically
not enabled on ports that connect to switches because spanning tree loops might
occur.
BPDU Features
Switches exchange special frames called BPDUs to communicate network
information, to track changes, and to create the STP topology. Because
transmitted BPDUs reveal network information and received BPDUs can
influence your STP topology, you might find it useful to enable BPDU Filtering
and BPDU Guard on your access ports. These features prevent a rogue device
from interfering with your STP topology. However, we recommend you use these
features with caution:
• BPDU Filtering—This PortFast feature blocks all sending and receiving of
BPDUs through all PortFast-enabled ports. This feature effectively
disables STP on these ports and loops can result. If a BPDU is received,
PortFast is disabled on the port and the global STP settings apply. To
enable BPDU Filtering on all PortFast-enabled ports, check Enable.
• BPDU Guard—This PortFast feature shuts down a port if it receives a
BPDU. To enable BPDU Guard on all Port Fast-enabled ports, check
Enable.
Note that if you enable both of these features, BPDU Guard has no effect because
BPDU Filtering prevents the port from receiving any BPDUs.